Home
Introduction
Talmudic Issues
Essays
The Sweat-Louse, the Dirt-Mouse, and the Dong-Chong
by Rabbi Nosson Slifkin Are all mice born from other mice, or are some of them born from dirt? Are lambs always born from sheep, or can they sometimes grow from vegetables? For most of history it has been widely accepted that animals can come into existence through spontaneous generation – that is to say, they are not born of other animals. In Jewish literature we find several mentions of such phenomena. Halachos pertaining to such creatures are ruled upon. Yet contemporary science rejects spontaneous generation as being a totally mistaken belief. Recently, a Talmud scholar in Israel who became irreligious published a series of leaflets that highlighted problems and difficulties in Torah literature. The first of these dealt with the topic of spontaneous generation. The leaflet cited all of the Torah sources that accept this phenomenon, and none of those that reject it. Ostensibly, it merely presented the point that Chazal’s knowledge of science was no better than that of gentile scholars of their era. But the derisive style of writing, and the content of further leaflets, made other points: that Torah scholars throughout the generations have been gullible and naive, and in some cases foolish and intellectually dishonest. Are his conclusions correct? Orthodox Jews believe that the views of Torah scholars through the ages must be treated with great respect. Furthermore, contrary to popular opinion, it is accepted that the further back in time one goes, the greater the stature of the scholars. The Sages of the Talmud were spiritual giants, whose greatness we cannot fathom. Yet this does not preclude a rational and reasonable discussion of conflicts between sages and scientists. This essay analyzes the topic of spontaneous generation in depth, including the implications for those who believed in the phenomenon, and the ramifications of the Torah laws that deal with it. I. The Sweat-Louse The Talmud states that lice spontaneously generate:
Some variant texts state that lice “do not reproduce by way of male and female.” Certain species of lice reproduce parthenogenically, meaning that females reproduce by themselves. No male louse has ever been found (although there are some women who disagree with this!). Thus, it is proposed that the Talmud is not stating that lice do not come from eggs, only that these eggs do not come from the conventional system of males and females. However, this resolution is problematic. The lice that are found on humans do not reproduce in this way, but rather through males and females. Additionally, if the Talmud was speaking about females laying eggs, it would have no difficulty with statement about God sustaining the eggs of lice. Furthermore, none of the classical commentaries on the Talmud understood it in that way. Tosafos (to Shabbos 12a) states that the type of louse known as the rocheshes is generated from human sweat. The Ran states that lice are generated from dust. There are two issues that must be dealt with: 1) Is the statement of the Gemara, that lice do not reproduce via eggs, true? 2) If it is not true, what are the ramifications for the halachah and for the stature of the Sages? Is it True? With regard to the first question, contemporary knowledge of the natural world tells us that it is not true. All animals are born from other animals. In ancient times, people did not realize this, because they had less of an understanding of the natural world, and the eggs of certain insects are too small to be seen with the naked eye. They therefore believed that insects emerge from sweat and dirt. A dissenting view is that of Professor Herman Branover, who writes:
There are several objections to be raised on this paragraph, such as that adherents of evolution do not accept spontaneous generation. However, let us address the main point, that we can only prove something but can never disprove the existence of something. While it is technically true to say that we can never categorically disprove the existence of something, there are nevertheless many cases where we are absolutely confident that certain things do not exist. Let us consider, for example, vampires – in the sense of people who change into bats. We cannot conclusively prove that they do not exist. There have been, throughout history, many people who have firmly believed in such things. Yet we are utterly certain that they do not exist, for three reasons. First, all our knowledge of the world tells us that it is physically impossible for a person to transform into a bat. Second, we have good reason to believe that the vampire legend is based on kernels of true facts that were subsequently distorted, such as the existence of vampire bats that suck blood, and the existence of certain people with bizarre habits. Third, if vampires did exist, we would expect to find evidence of them. Putting these three reasons together tells us that it is overwhelmingly more likely that the vampire legend is based on mistaken information rather than on an actual phenomenon. Thus, even though we cannot actually prove that vampires do not exist, we still do not believe that they do. Similarly, we would firmly state that fairies, leprechauns, and fire-breathing dragons do not exist, even though we cannot prove this. They are biologically improbable, and there is good reason to state that accounts of them are based on mistakes or tall stories; and if they did exist, why has no evidence of them been discovered? If we turn to spontaneous generation, the same is true. All of our experience tells us that everything happens with a prior cause – with the possible exception of the beginning of the universe itself (to which we attribute a spiritual cause but no physical cause). In all the studies that have been made of the world, in all the video footage that has been shot, nobody has ever seen an animal pop into existence except where being born from another creature. Lice are born from other lice; they are not spontaneously generated from sweat or dirt. Why Would People Believe It? Now let us explore if there is reason to believe that accounts of spontaneous generation are based on mistakes rather than genuine phenomena. But first, we must respond to the suggestion that the Sages were not speaking about the lice with which we are familiar, but instead about a particular species of lice that is currently unknown to us (or extinct) and does indeed spontaneously generate. This is extremely unreasonable. Until the late 17th century, the entire world believed that lice (as well as many other creatures) are spontaneously generated. It is highly unreasonable to state that when the Sages spoke of spontaneously generating lice, they were speaking not of the lice that the entire world mistakenly believed to be spontaneously generated, but instead of a different species that is currently unknown. It would have been a ruling that would have been totally misunderstood by everyone! There is good reason to believe that the statement of the Sages is based on flawed information. As we noted, the entire world used to believe that spontaneous generation occurs with a wide range of creatures. An excellent discussion of this topic is to be found in Jan Bondeson’s fascinating work, The Feejee Mermaid and Other Essays in Natural and Unnatural History, (New York: Cornell University Press 1999), from which the following sources are taken. Aristotle wrote that certain lower animals “are not produced from animals at all, but arise spontaneously: some are produced out of the dew which falls on foliage... others are produced in putrefying mud and dung, others in wood, green or dry, others in residues, whether voided residues or residues still within the living animal.” Eels and fishes come from the foam of the sea, insects from sand whirled into air by wind, and wasps from cadavers of dead horses. One Sir Thomas Browne did not disagree with the concept of spontaneous generation, but he doubted whether this could also include mice. Alexander Ross, an Aristotelian, wrote in response: He doubts whether mice can be formed of putrefaction! So may he doubt whether in cheese and timber worms are generated; or if butterflies, locusts, grass hoppers, sel-fish, snails, eels and such are procreated of putrefied matter... To doubt this is to question Reason, Sense, and Experience... The Egyptians believed that insects, frogs, mice, crocodiles and other strange creatures could be generated in the fertile humus left by the flooding of the Nile. The Roman poet Virgil in his Georgics writes that bees are formed from the flesh of oxen. Arab naturalists in the Middle Ages accepted Aristotle’s teachings, and suggested that even humans could arise from putrefying matter. The influential Italian mathematician, naturalist and physician Girolamo Carano included a large section in his de Subtilitate on spontaneous generation, in which he explained that not only ants, flies, fish, and crayfish, but even mice, hares, and gazelles were regularly born this way. When theologian Wolfgang Franzius published his Historia Animalium Sacra in 1612, claiming that no animal could be born without parents, he was ridiculed as being completely ignorant of modern biology. Where did these ideas come from? They are likely to be simply due to the fact that it did not occur to anyone to think differently. Meat left out to rot would soon swarm with maggots. Nobody had watched flies lay eggs, and many of these eggs would either not have been visible to the naked eye, or not recognizable as eggs. It seemed obvious that the meat itself was generating the insects. There was no systemized study of science in those days to prove otherwise. There is an interesting phenomenon that may, at least in part, have contributed towards the myth of spontaneous generation. The burrowing frog lives in arid regions and deserts. At the start of a long dry spell, when the pools from the last rainstorms are in the last stages of evaporation, the frog buries itself up to twelve inches deep in the mud. There it settles into a state of suspended animation, with its breathing and heartbeat slowing to a rate just sufficient to keep it alive. After about two weeks, the outer layers of the frog’s skin detach and meld together into a membrane that is fully waterproof apart from two tiny tubes to the frog’s nostrils. The frog can survive in this state amidst desert drought for many years. Then, when the rainfall finally comes and turns the sand into mud, the frog breaks out if its bag and emerges upon the surface, appearing to have grown from the mud. 
Figure 1: A burrowing frog emerging from its sac For whatever the reasons, spontaneous generation was widely accepted well into the seventeenth century. A change occurred in 1636 when physician and philosopher Daniel Sennert published his Hypomnemata Physica, claiming that new life could generate only from once living matter – flies could be engendered from meat, but not from dirt. Yet philosopher Rene Descartes disagreed. It was only towards the end of the seventeenth century that experiments by Francesco Redi and Louis Pasteur surprised the world by proving that substances that were protected from the air did not produce insects. The myth of spontaneous generation was finally laid to rest. The Implications About The Sages Many people are uncomfortable with this topic, because of the ramifications for the Talmud. One feared ramification is that it demonstrates the Sages to have been gullible or foolish. Another is that it means that the law about killing lice on Shabbos should be changed – and once one starts changing laws, who knows where that will end? The response to the first concern is that the belief of the Sages in spontaneous generation does not mean that they were at all gullible or foolish. Gullibility has to be measured against the knowledge that one already possesses. For example, if a newspaper were to report that a new species of monkey, two feet in height, with Mohawk-style hair, no thumbs, a bright red face, and a long nose that droops over its mouth, has been discovered in the rainforests of Costa Rica, the average person might be skeptical. However, a zoologist, who possesses a thorough knowledge of the animal kingdom, would not be so skeptical. For there actually are species of monkeys with Mohawk-style hair, red faces, no thumbs, and a droopy nose. If, however, the newspaper reported that a new species of monkey was discovered with dark green fur, there would be no particular reason for the average person not to believe it. But the zoologist would have reason to be skeptical, for not one of the 5,000 known species of mammals is green. In ancient times, based on the information available, there was no particular reason not to believe in spontaneous generation. As we have seen, there were kernels of truth in observations of spontaneous generation. Nobody had ever performed experiments to disprove it. There was no systemized knowledge of the natural world. It was perfectly reasonable to believe in spontaneous generation, and we should not scorn the people of that era for being gullible, any more than we would criticize the average person for believing in a turquoise monkey. In any case, it should be noted that there seem to be far fewer citations of mythical creatures in Jewish texts than in other texts. Perek Shirah, for example, the classical Jewish work of natural history, lists only known animals, while the Christian bestiaries, which were moralizing fables, featured a host of mythical creatures. Sages and Scientists Rambam, in discussing scientific statements made by Chazal, gives us an important principle:
Following in his father’s footsteps, Rabbeinu Avraham ben HaRambam states:
Rabbi Samson Raphael Hirsch (d. 1888) writes as follows:
Rabbi Hirsch cites as proof the following Gemara:
The topic of Chazal’s knowledge of science is a complex one that cannot be adequately dealt with in this forum. An excellent work on the subject is Hishtanus HaTevi’im by Rabbi Nuria Guttal. There are some views which state that Chazal did indeed possess a superior or perfect knowledge of science, such as that of Rabbeinu Tam, the Rema, the Chidah, and the Aruch HaShulchan. Yet, as shown here, there are certainly authoritative views, based on the straightforward understanding of the statement of Rebbi himself, which do not consider that their knowledge of science was any different than anyone else of that era. With the case of lice, recent scholars do understand that Chazal were mistaken in explaining that they spontaneously generate; it is only the legal ramifications of this that are subject to dispute, as we shall now explore. There is a suggestion, which is commonly heard, that follows the approach of saying that the Sages of the Talmud could not have made a mistake about natural phenomena. According to this approach, the Sages were not speaking about the lice with which we are familiar and hatch from miniscule eggs, but instead about a particular species of lice that is currently unknown to us (or extinct ) and does indeed spontaneously generate. This is extremely unreasonable. As we have seen, until the late 17th century, the entire world believed that lice (as well as many other creatures) are spontaneously generated. It is highly unreasonable to state that when the Sages spoke of spontaneously generating lice, they were speaking not of the lice that the entire world mistakenly believed to be spontaneously generated, but instead of a different species that is currently unknown. Furthermore, it would have been a ruling that would have been totally misunderstood, and misapplied, by almost everyone! Suppose one posits that the sages of the Talmud possessed impeccable knowledge of nature and could only have been speaking about lice that really do spontaneously generate. But they must also surely have known that many simple people of their generation, and of subsequent generations, believed that ordinary lice are also born through spontaneous generation, and would transgress Shabbos by killing them! And consider how, throughout the ages, the commentaries on the Talmud spoke of the permissibility of killing lice on Shabbos due to their spontaneous generation. The recent authorities were certainly speaking of the same lice with which we are familiar. If we posit that the Talmud itself was speaking only of a particular louse that really does spontaneously generate, then at which point did this ruling become entirely misunderstood and misapplied to ordinary lice? For all these reasons, it is extraordinarily unreasonable to posit that the sages were not speaking of the ordinary lice with which we have been familiar for generations, but instead of an unknown species. We must accept that they were speaking of the same lice that Rambam, the Shulchan Aruch and Mishnah Berurah understood them to be speaking of – the lice which we all know. Legal Ramifications We have established that lice are not born via spontaneous generation, and the Sages were mistaken in stating that such is the case. The question now is what to do about the ruling that one may kill lice on Shabbos. This problem was first addressed by Rabbi Yitzchok Lampronti (d. 1756), author of the Talmudic encyclopedia Pachad Yitzchak, and mentor of the renowned Rabbi Moshe Chaim Luzzatto. He cites an opinion on this matter from Rabbi Yehudah Brill (d. 1722) of Italy: Rabbi Brill states that the law still stands – apparently because there are hidden reasons for it that elude us, rather than because Chazal are actually correct regarding spontaneous generation. But Rabbi Lampronti himself tentatively disagrees:
In contrast to this is the view of Rabbi Eliyahu Dessler. In a footnote to Michtav Me-Eliyahu, Rabbi Aryeh Carmell, one of Rabbi Dessler’s foremost students, writes as follows:
It is fascinating to contrast Rav Dessler’s approach with that of the cited Rav Lampronti. Dealing with laws of Shabbos, which are extremely stringent, Rav Dessler does not even see any cause to prohibit killing lice just to be “on the safe side.” (Note that Rav Lampronti himself does not say that the halachah is clearly to be changed; he just wishes to cover all possibilities.) Rav Dessler’s conviction in the ultimate truth of the halachah dictates that there is simply no need to take this precaution (and there is perhaps even an element of heresy involved in trying to be “on the safe side”). Some claim that the explanations described by Rabbi Carmell was actually the intent of the Gemara; Chazal actually meant only that the eggs of lice are halachically insignificant, not that they don’t exist. But aside from this being an unreasonable explanation of the words of the Gemara, and lacking any proof, there is a straightforward refutation of this argument. Why would Chazal then reject the simple meaning of the statements that speak about the eggs of lice? Let them simply state that although lice do hatch from eggs, these are too small to be halachically significant! It is clear that they did not consider this possibility. Neither Rav Lampronti nor Rav Dessler stated that Chazal were referring to a type of louse that actually does spontaneously generate. Strangely, the Mishnah Berurah (316:9:38) does state that lice are born through spontaneous generation. It is unclear whether the Chafetz Chaim was simply unaware of the advances of science, if he disagreed with them, if he considered them irrelevant to the halachic discussion, or if he had reasons not to involve himself in this topic. In summary: the statement of the Gemara that lice spontaneously generate is mistaken. This has no derogatory explanations whatsoever for the stature of the Sages (unless one formerly considered them to be omniscient, a distinction usually reserved for God alone). The halachic implications, however, are disputed. II. Vegetable Humanoids and Lambs Another intriguing case of an animal that is not born of parents is found in the Mishnah. There is a discussion of the laws concerning a peculiar creature known as the adnei ha-sadeh, literally “master of the field”: What is the adnei ha-sadeh? Rabbi Ovadia MiBartenura explains:
The yidoni to which he refers is the medium of sorcery prohibited in the Torah:
Rashi explains that the yidoni practice refers to a person taking the bone of a creature called yedua, placing it in his mouth, and causing it to speak. The Talmud also discusses such a creature: It should be noted that this explanation of the adnei ha-sadeh is not the only explanation. Rabbi Yisrael Lipschutz (d. 1860), in his Tiferes Yisrael commentary, explains the adnei ha-sadeh to refer to a different animal entirely: Nevertheless, the Tiferes Yisrael himself cites the alternate view. He defends the general criticism of it, but himself raises questions as to its biological viability: The Tiferes Yisrael’s position is therefore that one can certainly challenge the biological statements of Rishonim. However, those statements of the Talmud must be treated with greater respect. He firmly respects the statement concerning the mouse that grows from the ground, which we shall soon discuss, and also states that were the Talmud to speak of the existence of the cord, “perhaps such would be the truth.” The yidoni legend may also have an alternate version. The botanist Claude Duret, in his 1605 work Histoire Admirable des Plantes, writes that he “remembers having read” a text of the Talmud Yerushalmi which refer to the yidoni as being a lamb that grows from the ground rather than a humanoid. Various other secular works also speak of an ancient Hebrew legend in which the creature is shaped like a lamb, not a humanoid. The 1705 work Ma’aseh Tuviah (4:10) to which Rabbi Lipschutz referred above cites both the description of a humanoid and a contemporary account of a it taking the shape of a lamb, and concludes that the lamb account is more likely to be true that the humanoid account. 
Figure 2: A vegetable lamb, from Claude Duret's Histoire Admirable des Plantes The relevance of this alternate version is that the “vegetable lamb” was widely reported throughout the world in earlier centuries. The first accounts are in Chinese manuscripts, one dating before the year 429. In Europe, similar accounts later became widespread. The knight Sir John Mandeville wrote in 1356 that, when visiting Tartary, he had been served a lamb that grew on a stalk from the ground. Similar accounts of the “Vegetable Lamb of Tartary,” which was also known as the Boramez, became widely accepted. Imported skins of lambs that had supposedly grown from the ground fetched high prices. It was only in the year 1698 that a complete specimen of a vegetable lamb, acquired from a Chinese collection of curiosities, reached European naturalists. Sir Hans Sloan of the Royal Society of London demonstrated this strange thing, which resembled a woolly branch with four legs. He was also able to determine what it really was: the large rootstock of a fern, ingeniously carved to look like a lamb. He was proved correct when the first of these unusual ferns was brought to Europe; they were named cibotium borametz, in honor of the Boramez legend. It seems that these specimens were widely manufactured by Russians, Indians, and Chinese, who were skilful at fabricating the rootstocks into small animals. One beautiful example is on display at the Museum of Garden History in Lambeth, England; it really looks quite remarkable. 
Figure 3: The vegetable lamb at the Museum of Garden History As with the sweat-louse, we can confidently state that no creatures grow from plants. It would stand in contradiction to everything that we know about zoology (and botany), and there is a good explanation to account for the formerly prevalent belief in such things. Does all this mean that this discussion of Chazal is now worthless, and to be consigned to the history books? Far from it. Let us first explore our final case of claimed spontaneous generation, after which we shall discuss the benefit of these sections of Torah. III. The Dirt-Mouse Our final case of spontaneous generation is that of a certain rodent. The Mishnah discusses the laws concerning a mouse that is half formed of earth.
This creature supposedly grows from the earth, and thus passes through a stage in which it is part earth and part mouse. It is also cited in the Talmud as a proof for the resurrection of the dead:
As with the lice, and the yidoni, we can confidently state that this creature does not actually exist. There is no biological explanation for such a phenomenon, and there is good reason to believe that it is based on mistaken observations. Rambam, in an interesting comment on this Mishnah, may also hint to a certain skepticism:
There are two ways of understanding Rambam. One could say that he is confidently supporting the existence of this creature. Alternatively, one could say that the fact of his acknowledging the existence of such a creature is not so important; as he states, he is basing his opinion on a large amount of eyewitness testimony. What is important to note is that Rambam sees fit to debate the authenticity of such a creature. He does not blithely go with the Mishnah. Rather, he was “astonished” that such a creature could exist, and sees it as necessary to cite eyewitnesses in order to allay doubts, not faith in the Sages of the Mishnah. This would be consistent with the position of Rambam cited earlier that he did not consider that the Sages possessed perfect scientific knowledge. A fascinating addendum is written parenthetically by the Tosafos Yom Tov:
Kadmus> was a theory prevalent for much of history. It posited that there is no prior cause for physical existence; rather, the universe has always existed in the state that in which it exists today, and mice have always been descended from earlier mice. A creature that is born from inanimate matter refutes such a theory, and indicates that the universe can indeed pop into existence ex nihilo. The science of today does not subscribe to the theory of kadmus. The current understanding is that the universe inexplicably sprang into existence a long time ago. However, this does not prove that mice can also inexplicably spring into existence. Rabbi Yisrael Lipschutz, in his commentary Tiferes Yisrael, defends the existence of this creature:
However, Professor Sid Z. Leiman, in an article entitled R. Israel Lipshutz and the Mouse that is Half Flesh and Half Earth: A Note on Torah U-Madda in the Nineteenth Century (printed in Hazon Nahum, New York: Yeshivah University 1998), has demonstrated that Rabbi Lipshutz actually misunderstood Link. Heinrich Friedrich Link (1767-1850) was a German botanist and Zoologist. The full title of the book cited by Rabbi Lipshutz is (in translation) “The Primeval World and Antiquity Elucidated by Natural History.” In discussing ancient Egypt, Link cites Diodorus Siculus, a first-century B.C.E. Greek historian, who reports that the Egyptians state that life first began in Egypt, and as proof of this, they note that mice are generated in vast numbers from the soil of their land. Diodorus himself concurs that this takes place:
Here is where Link himself adds a footnote to the account of Diodorus: The animal being referred to is the jerboa. The jerboas are a family of tiny to large rodents that have long back legs for jumping and dig burrows in which they sleep. One of the three subfamilies is known as Dipodinae and it includes the genus Jaculus; this is the dipus jaculus mentioned by Link. 
Figure 4: A jerboa Professor Leiman points out that Rabbi Lipshutz appears to have made several mistakes in his citation of Link. Link is not stating that dipus jaculus grows from the ground. He merely states that its tiny forearms look like those of a creature that is incomplete. (Actually, the tiny forearms of the jerboa are perfectly suited to the jerboa’s lifestyle.) It is certain that Link himself, who lived in the nineteenth century, and was very familiar with the jerboa, did not believe that it or any other animal grows from the ground. Rather, he is saying that this creature may be the source of the Egyptian myth. Rabbi Lipshutz, on the other hand, understood Link to be saying that dipus jaculus actually was the creature that the Egyptians spoke of. Hence, he mistakenly stated that dipus jaculus is an Egyptian, rather than Latin, name. Furthermore, he took Link to be attesting to this creature growing from the ground. The approach of Rabbi Lipshutz, with its errors, is peculiar. This is especially so when we consider his very different approach with the adnei ha-sadeh; but we should not forget the context in which he was speaking here – to refute “the heretics.” Presumably he is referring to people who used such a claim to scorn the Torah in general; he states that they were “mocking,” and he therefore preferred to use the citation from Link rather than to search for a more rational explanation. Yet not all people who deny the existence of such a creature are heretics; there are approaches that also suggest that the scientific data may be inaccurate, but which do so in a way that in no way belittles Chazal. We have already seen the approaches of Rabbi Lampronti and Rabbi Dessler regarding spontaneously generating insects; let us now explore the approach of Rabbi Samson Raphael Hirsch to this case in particular. He writes: Rabbi Samson Raphael Hirsch explains that Chazal were simply giving a ruling for a case that was presented to them. They did not take it upon themselves to verify whether or not such creatures existed, just as the Torah scholars of Rabbi Hirsch’s day would readily accept the testimony of Alexander von Humboldt (1769-1859), a famous German naturalist. If we now think that such creatures never existed, it does not affect the standing of Chazal. (In contrast to this position is that of Rabbi Yehoshua Heller of Telz, who writes in his work Maoz Ha-Das that if Chazal describe such a creature, it must exist.) As Rabbi Hirsch notes, for centuries, most information about the natural world was grounded in the writings of Pliny the Elder (23?-79 CE). He was a Roman civil servant and cavalry officer who collected stories about animals and believed everything he was told. Pliny took Aristotle’s Historia Animalium and extended it into the thirty-seven volume Historia Naturalis. This work contained an extraordinary range of superstitions and folklore about animals. Unfortunately, Pliny’s work became the standard reference upon which all future works were based. Thus, fantasy and folklore became widely accepted as fact. Rabbi Aryeh Carmell suggested to me that the creature concerned is a mole. As it emerges from the earth, people could mistakenly believe that it is growing from the earth. The same could apply to the jerboa. Rabbi Mordecai Kornfeld suggested to me that the myth grew from the frogs that emerge from earth, as discussed earlier. IV. Dong Chongs and Ear-Mice Rabbi Samson Raphael Hirsch’s explanation concerning both the yidoni and the dirt-mouse is that Chazal simply gave the legal ruling concerning the creatures that were reported to exist; they did not investigate whether these reports were actually true. But the reason why they did not investigate these reports was not only for lack of resources. It was also because there was value to discussing such rulings. The study of Torah is not only for the purpose of practical law; it is an end unto itself. The classical example of this is with ben sorer u’morer, the rebellious son who is put to death. The criteria for a child to be classified as a ben sorer u’morer are such that it is virtually impossible for such a case ever to actually occur. It is a practical impossibility, but we study its laws for the sake of the study itself. Even if there is no such creature as the earth-mouse or the vegetable-lamb, the study of their theoretical laws is still Torah. An example of this approach is found in a Tosafos that discusses the usage of an animal as a cover for a coffin: This also provides a response to Rabbi Heller’s argument in defense of such creatures that if the Torah discusses it, it must ipso facto exist. Ben sorer u’morer proves that the Torah includes, and even mandates, the discussion of cases that do not and cannot exist. The study of fictional cases is also Torah. And it may well have practical applications in cases that are yet to be discovered. The Dong Chong An example of why it may be relevant to discuss fictitious creatures that do not fall into just one of the, is the dong chong xia cao. In 1993, at the National Games in Beijing, China, three Chinese women long-distance runners set new world records for three different distances – the 10,000m, 15,000m and 30,000m. This outcome shocked the sports world and investigations ensued. It was discovered that their coach, along with his intensive training, was giving the runners an herbal tonic prepared with high concentration of the Chinese Cordyceps drug. Originally produced in Norway, but used in Chinese medicine for thousands of years, this immune-boosting, performance-enhancing compound was a trade secret until 1996, when the secret was uncovered. It comes from a creature that the Chinese call dong chong xia cao, which means “winter worm, summer grass.” The bizarre facts of this is that the Hepialus moth, found only in the high and cold elevations of China's mountains, produces a soil-inhabiting caterpillar that becomes active in the late summer and eventually is infested by the Cordyceps fungus. At the beginning of autumn, the Cordyceps fungus releases its spores and invades the caterpillars. The fungus slowly eats away the tissues of the hibernating caterpillars throughout winter, filling them up with long filaments. By spring, the caterpillars sprout long stalks, which are revealed when the snow melts. (Source) Thus, we see that it is possible for there to be a single unit that, in a way, is both a plant and an animal. The categories of animal, vegetable and mineral are not always as distinct as we would expect. The dong chong xia cao is not directly relevant to the Torah cases that we are discussing, but does provide a lesson in humility for the skeptic. One never knows when there might be a situation for which the cases discussed in the Torah would have a practical application. The Ear Mouse But there is an even more remarkable creature that may present a direct ramification of the halachah concerning the mouse that is part earth. This is not a species of creature, but rather a particular mouse, in the laboratory of University of Massachusetts anesthesiologist Dr. Charles Vacanti, that has a human ear growing on its back. The mouse was created for children who lose their ears while fighting in school(!). Linda Griffith-Cima, an assistant professor of chemical engineering at M.I.T., created an ear-like scaffolding of porous, biodegradable polyester fabric. Then she and Vacanti distributed human cartilage cells throughout the form, and implanted the prototype ear on the back of a hairless mouse. The mouse, specially bred to lack an immune system that might reject the human tissue, nourished the ear as the cartilage cells grew to replace the fiber. The end result is a human ear that can be transplanted to the child that lost his own. The researchers said that the mouse remains healthy and alive after the ear is removed. 
Figure : The remarkable ear-mouse The ear-mouse may well fall into the category of the part-flesh, part-dirt mouse mentioned in the Mishnah – or at the very least, the discussions on the Mishnah would be highly relevant to this case. If this mouse were to die, which parts of it would render one tamei if touched? If the polyester fabric, implanted with human cartilage cells, is considered like earth, then one is not tamei if one touches it. This extraordinary case, unthinkable several years ago, serves to illustrate that discussing laws of creatures such as the dirt-mouse and the vegetable lamb, aside from their theoretical value of Torah study for its own sake, may as yet prove to have practical ramifications. V. Conclusion Spontaneous generation, a phenomenon accepted until a few centuries ago, and described in three cases in Torah literature, has been proven false. To deny this is to go against all reason. More recent Torah scholars have recognized this fact, and Chazal never considered themselves omniscient in the first place. But those who would scoff at Torah literature for discussing such creatures are in error. They forget that they, too, would believe in such things, were it not for the accumulation of knowledge over the last few centuries. And it is always unwise to ridicule people’s knowledge of the natural world, as it is always full of surprises; who would have guessed that there is a caterpillar that grows like a plant? Furthermore, these areas of Torah law have not been proven irrelevant. Torah study is relevant for its own sake, whether or not the cases it describes actually exist. Cases of spontaneous generation, true or false, serve all the better to plumb the depths of halachah. And finally, one never knows when such halachic discussions will prove relevant. Does the ear on the back of the mouse at the University of Massachusetts transmit tum’ah? In determining the answer, the Mishnah’s discussion of the earth-mouse is the first place to look. The Sages may not have been correct when they said that lice spontaneously generate, but they were certainly correct when they said,
© Nosson Slifkin 2001, www.zootorah.com This essay is adapted from Rabbi Slifkin's book, Mysterious Creatures, soon to be published by Targum Press. It is printed here with permission.
|