482 



NATURE 



\August 29, 1878 



curious fact that they differed very materially. The sacrum is 

 generally figured as being composed of five vertebral element?, 

 but he had frequently found six, and in one case seven. A 

 friend had told him that he had seen one with only four. Of 

 the five usual sacral vertebrae the two lower are generally figured 

 as having gaps in the neural arches, but it was his experience 

 that it was more usual to find the gap also in the third, and he 

 had seen sacra in which there was only one neural arch. He 

 had not studied the sacra and coccyges of any of the tailless 

 vertebrata but the guinea pig, but even in it he had found curious 

 variations, chiefly in the length and number of the coccygeal 

 centre, and he assumed that in such an early type such variations 

 must of necessity be less marked than in the later ones. He 

 thought it likely that spina bifida was not confined to the human 

 animal. In the human animal its most common seat is the 

 sacral and lower lumbar vertebrae. It was fair to assume, 

 therefore, that in a tailed vertebrate it would occur more 

 frequently in the tail than elsewhere. If this be the case, 

 and if, likewise, it ever does occur amongst animals not domesti- 

 cated, it will most certainly occur occasionally that a tailless 

 vertebrate will, by reason of a spina bifida, be born of properly 

 tailed parents. If the deformity was sufficiently high up 

 to destroy the tail, yet not high enough to interfere with 

 the nervous supply to the posterior limbs, then he might 

 survive in the struggle for existence, provided the tail was 

 not essential to life. They could easily imagine that under 

 favourable circumstances a monkey born with this change 

 in his economy might strike out a new line of life, breed 

 tailless children, and by the change of other structure ne- 

 cessitated by the new method of life, introduce a new variety 

 of monkey. Those who were still opposed to the evolutionary 

 view of creation might sneer at this as a series of "ifs," but 

 they must be reminded that the whole of Hfe — individual and 

 collective — is but a change of circumstances, precedent to any 

 one of which an "if" can be introduced, and that had "if ' 

 really been effective the whole chain would have been different 

 from that point. What, then, was the significance which might 

 be attached to the sacral dimple which was the subject of the 

 paper ? Looking at it surgically there could be no qitestion that 

 it was a cicatrix. What he ventured to suggest was that it was 

 the hereditary cicatri^j of the spina bifida by which the human 

 tail had been lost. Such a suggestion was of course open to 

 ridicule, but only, he ventured to think, in the minds of the 

 incautious or the ignorant. That man was.once a tailed verte- 

 brate was beyond doubt, and that he lost his tail was, of course, 

 equally evident. He was not the only vertebrate who had lost 

 a tail, and in whatever way those tails had been lost they had 

 evidently all been lost in the same way. Now, curiously enough, 

 they had an animal living in one of the sister isles of which not 

 a genus, nor a species, nor a variety, but a mere family had lost 

 its tail ; he referred of course to the Manx cat. He had obtained 

 some of these cats from the Isle of Man, and he was quite 

 certain that if they knew the history of this curious family of 

 cats they should know exactly how all the vertebrates which are 

 now tailless became so, and he felt very confident that the Manx 

 cats lost their tails through the occurrence, within very recent 

 times, of a tom cat with a spina bifida placed exactly where it 

 was in the case of the kitten he had referred to. A limited area 

 like Man would present the most favourable c'rcumstances for 

 the protection and propagation of such a variation ; for he 

 (Mr. Tait) had already elsewhere pointed out that the bushy tail 

 of such animals as the cat served chiefly for the purpose of 

 maintaining temperature, and in the mild and equal climate of 

 the charming island a tailless cat would have little hardship to 

 endure. It could not have survived, however, in any place 

 where snow lay long on the ground. In the few Manx cats he 

 had examined he had seen no trace of dimple, nor had he seen 

 any appearance of it in the guinea pig ; but these negative results 

 did not seem to him to be important. What would be impor- 

 tant would be the examination of a number of tailless monkeys, 

 especially young ones. If in these no dimple was to be found, 

 then he feared they should have to look forward to some other 

 history for this curious cicatrix. 



The president said he was not inclined to take the same view 

 as Mr. Lawson Tait as to the means by which the tail in the 

 human species had been got rid of. It appeared to him that 

 what Mr. Tait had described was more likely to be the remains 

 of infantile spina bifida. It was all very well for human beings 

 to object to their having tails, but, as a matter of fact, they had 

 tails, though they had disappeared to very small dimensions, in 

 which they row existed in the h-i-rian family. 



Department of Zoology and Botany. 



On the Remains of a Permian Fauna in North America, by 

 Prof. E. D. Cope, U.S.A. — Prof. Cope described the remains 

 of a fauna, now extinct, which had inhabited North America 

 during the j^eriod of geologic time next succeeding the coal mea- 

 sures, which is known as the Permian. He had first ascertained 

 its existence through specimens sent from Illinois in 1875, but 

 had discovered much larger deposits of similar animals in Texas. 

 The characters of the latter showed that they were to be referred 

 to the classes Reptilia and Batrachia. A number of generic 

 types of reptiles were mentioned, most of which are charac- 

 terised by the notochordal vertebrae. He particularised the 

 characters of the dentition of Diadedes and Bolosatirus, where the 

 teeth are transverse to the long axis of the jaws. He entered 

 more fully into the structure of Clepsydrops, Cope, where almost 

 the entire skeleton had been discovered. This includes clawed 

 lizards, with large canine teeth and several incisors, humerus 

 without condyles, but with supracondylar foramen ; reptilian 

 posterior limb ; boat-shaped pelvis, without obturator foramen, 

 and with the neural spines of the sacral vertebrae greatly elevated 

 (in C. natalis). There are small intercentra between the inferior 

 parts of the adjacent centra, which support the chevron bones in 

 the tail. 



The Batrachia display remarkable characters of the vertebral 

 column. In Cricotus the intercentra are developed so as to 

 resemble centra, so that the column appears to consist of two 

 kinds of vertebra; alternating with each other. A neural arch 

 of the caudal series stands equally on centrum and intercentrum, 

 but the intercentrum only bears the chevron bone. 



Sir J. Lubbock read a paper On the Habits of Ants. — The 

 author observed that he had kept about thirty species of ants in 

 confinement. They throve well, and he had some specimens 

 which he had kept since 1874. They were probably bred in the 

 previous year, and would now, therefore, be five years old. He 

 also referred briefly to the other insects which were kept by ants 

 in their nests, and especially to aphides, some species of which 

 are kept and carefully tended by the ants throughout the winter, 

 though at that season they are not of any use. He referred 

 shortly to his experiments on the senses of ants. Their sense of 

 smell is very delicate, though much more so in some species 

 than in others. On the contrary, he had never observed any 

 proof that they are capable of hearing. As regards sight, be 

 had been able to satisfy himself tha.t they were capable of dis- 

 tinguishing colours, and that they are, for instance, very sensi- 

 tive to violet. The ants of a nest not only knew one another, 

 but they remembered one another even after a year's separation ; 

 and he recorded some experiments by which he attempted to 

 ascertain how the recognition is effected. He also referred 

 briefly to the insects which are domesticated by ants, and gave 

 a short account of the slave-making species, which are (at least 

 in one case) entirely dependent on their slaves, and would perish 

 even in the midst of plenty if left to themselves. He kept some 

 of these ants, however, alive for months by giving them a slave 

 for an hour a day to clean and feed them. The communities of 

 ants, he said, offer numerous analogies to those of men, and the 

 difference in the habits of the various species of ants are also in 

 this respect not without interest. The slave-making ants, in- 

 deed, represent an abnormal and, perhaps, only a temporary- 

 state of things, for it is not impossible that the slave-making 

 species will eventually find it impossible to compete with those- 

 which are more self-dependent and have reached a higher phase 

 of civilisation. But putting these species on one side, we find 

 in the different species of ants different conditions of life curiously 

 answering to the earlier stages of human progress — namely, the 

 hunting and pastoral, and even to the agricultural. For instance, 

 some species, such as Formica fusca, live principally on the 

 produce of the chase, for, though they feed partly on the honey- 

 dew of aphides, they have not domesticated these insects. These 

 species probably retain the habits once common to all ants. 

 They resemble moreover the lower races of men who subsist 

 mainly by hunting. Like these, they live in comparatively small 

 communities, and the instincts of collective action are little deve- 

 loped among them. They hunt singly, and their battles are 

 single combats like those of early history. Such species as 

 Lasius flavus represent a distinctly higher type of social life. 

 They may literally be said to have domesticated certain species 

 of aphides, and may be compared to the pastoral stage of human 

 progress, to the races which live on the produce of their flocts 

 and herds. Their commvmities are more numerous, they act 

 more in concert, their battles are no mere single combats, but 



