322 



SCIENCE. 



SOME RECENT AMERICAN PAPERS IN COM- 

 PARATIVE ANATOMY. 



Marsh, O. C. — The limbs of Sauranodon, with notice of a new species. 

 American ym<r>ial of Science, Feb. 1880, pp, 169-171 ; 1 figure. 



Morse, E. S. — On the Identity of the Ascending Process of the Astrag- 

 alus in Birds with the Intermedium. Anniversary Memoirs of the Boston 

 Society of Xatural History, 1880 ; pp. jo, 1 plate, 12 figures. 



Chapman, H. C. — The Placenta and Generative Apparatus of the Ele- 

 phant. Journal of the Academy of Natural Sciences cf Philadelphia, 

 VIII, 1880. 4 plates, 1 figure, 11 pages. 



Chapman, H. C. — On the structure of the Orang Outang. Proceed- 

 ings of the Academy of Natural Sciences, 1880. 16 pages, 7 plates. 



Among the many surprises which science owes to the 

 paleontological discoveries of Professor Marsh, few are 

 more notable than the condition of the limbs in Saura- 

 nodon. In the present paper Professor Marsh describes 

 the limbs with some detail, and gives a figure of the reft 

 hind paddle of S. discus. In each limb the proximal seg- 

 ment consists of a single bone which undoubtedly repre- 

 sents the humerus or femur. The following four seg- 

 ment consist respectively of three, four, five and six ap- 

 proximately discoid pieces, which are interpreted as repre- 

 senting the bones of the antebrachium or crus, the two 

 rows of the carpalia or tarsalia, and the metacarpalia or 

 metatarsalia of the ordinary vertebrate limb. 



Regarding the carpalia or tarsalia as constituting a 

 single segment, Professor Marsh suggests the following 

 general names for the corresponding segments in the two 

 limbs : propodial, epipodial, mesopodial, metapodial, and 

 phalangial ; since the latter two terms have already been 

 employed there seems to be no reason why the other 

 thiee should not be accepted. 



The figure seems to demonstrate the normal presence 

 in this fossil reptile of six distinct digits or dactyls. 

 " This is a character not before observed in any air- 

 breathing vertebrate. Some of the Amphibians retain 

 remnants of a sixth digit, and IcJithyosaurtis often has, 

 outside of the phalanges, one or more rows of marginal 

 ossicles that probably represent lost digits. With these 

 exceptions, the normal number of five is not exceeded." 



This condition of things in Sauranodoti is worthy of 

 consideration in view of the not infrequent occurrence of 

 sexdigitism with man and others of the higher vertebrates. 

 Darwin had suggested that this anomaly might be due to 

 reversion, but (The Descent of Man, 1, 120, note) after- 

 ward reluctantly abandoned the hypothesis in consequence 

 of Gegenbaur's denial of the existence of more than the 

 regular number of digits in the Ichthyopteriga. His 

 original view is now strengthened by Professor Marsh's 

 account of the limbs of Sauranodon, but does not yet 

 serve to explain the occurrence of more than six digits 

 with man, the cat, and perhaps other mammals. 



The other striking peculiarity of the sauranodont limb 

 is the presence of three epipodial elements. All of them 

 articulate with the humerus or femur, and Prof. Marsh 

 suggests that the intermediate one represents the os in- 

 termedium which, in most air-breathing vertebrates, is 

 more closely associated with the mesopodial bones. He 

 thinks its proper place is indicated in Sauranodon, but 

 that, "in the process of differentiation this bone has been 

 gradually crowded out of its original position." 



In the paper cited Prof. Morse offers a different inter- 

 pretation ; " That the bone which he (Marsh) indicates 

 as the intermedium is really the fibula, and the bone 

 which he represents as the fibula is an outer tarsal bone 

 which, with its metatarsal and phalangeal bone in senes 

 becomes obliterated in time; that, in the process of dif- 

 ferentiation, the intermedium is as likely to be partially 

 compassed by the distal extremities of the tibia and fibula, 

 as that a third bone of this (epipodial') segment had been 

 crowded down into the tarsal series." Pending the dis- 

 COVerj of new facts in paleontology, embryologv, or com- 

 parative anatomy, it is probable that most anatomists will 

 be predisposed toward the view of Professor Morse. 



Thos.- who are interested in the general morphology 

 of tlic vertebrate limb should not fail to read the sugges- 



tive facts and considerations presented by Prof. Huxley 

 in his paper on Ceratodus, Proc. Zool. Soc. of London, 

 Jan. 4, 1876. 



Most of Professor Morse's paper consists in the presen- 

 tation of facts in corroboration of the opinion advanced 

 by him in 1872, that the intermedium is represented in 

 most birds by the so-called " ascending process of the 

 astragalus " which, in an embryo heron, had been found 

 by the late Professor Jeffries Wyman to have a separate 

 centre of ossification. Figures are given of the parts as 

 they exist in several aquatic species, and there seems to 

 be no reason for doubting the correctness of Professor 

 Morse's conclusions. Our author also reproduces 

 Cuvier's figure of the tarsal region of the " Honfleur Rep- 

 tile," afterward named by Cope Lcelaps Gallicus, and 

 Cope's figures of the same parts of Loelaps and Ornitho- 

 tarsus. He considers that the intermedium is distinctly 

 represented as an ascending process with Lalaps, but is in 

 doubt as to Omithotarsus, whether it is "represented by 

 the enlargement of the tibiale in front, or was a separate 

 bone which occupied the tossa on the anterior face of the 

 tibia." The manus of the sea-pigeon (Uria grylle) is 

 figured to show the interesting presence of "rudimentary 

 nails on the second and third fingers, findex and 

 medius)." 



Dr. Chapman has profited by the unusual opportunities 

 afforded to a zealous anatomist by the extensive zoologi- 

 cal garden of Philadelphia, and by the large menageries 

 which sometimes have their winter-quarters in the same 

 city, and the papers here cited contain important contri- 

 butions to our knowledge concerning two forms whose 

 structures and functions are far from thoroughly known. 



A young Indian Elephant was born on the 9th of March, 

 1880, the gestation having lasted either twenty months 

 and twenty days, or twenty-one months and fifteen days, 

 according as it is dated from the last or the first of the 

 seven observed opportunities for its commencement. 

 " Immediately after birth the mother rolled the young 

 one in the straw. The young elephant, a female, stood 

 30 inches (about 75 cm.) in height, measured from base 

 of trunk to root of tail 35 inches (about 88 cm.), and 

 weighed 213^ pounds (about 97 kilograms). It was per- 

 fectly formed and well-developed ; it was noticed imme- 

 diately that it sucked with the mouth, and not with the 

 trunk, as Buffon reasoned it must do — an error so often 

 repeated in works ou Natural History. 



Dr. Chapman was fortunate enough to obtain the fresh 

 membranes, and to have them well injected. The figures 

 and descriptions indicate that, as Turner had concluded 

 from less perfect materials, the placenta of the elephant 

 is deciduous as in the Primates and Carnivora, and zonu- 

 lar as in the latter group. 



The generative apparatus of the female elephant pre- 

 sents some peculiar features, and although our author 

 begins his concluding paragraph by saying, " it appears 

 to me that there can be little doubt now that the gener- 

 ative organs in both species of elephant are understood," 

 yet his admission, in a foot note, that what he had called 

 vagina may be really an elongated cervix uteri, will lead 

 other anatomists to avail themselves of any opportunity 

 that may present in itself for further study of this portion 

 of the proboscidean structure. 



The anatomical account of the Orang is full of interest- 

 ing facts and ideas, but most of them have been outlined 

 already in No. 25 of this Journal. Like nearly all of 

 the Orangs, whose brains have been examined, this ex- 

 ample was young, estimated to be about three years old. 

 The immaturity of the brain, together with the probability 

 of considerable individual variation in the details of the 

 cerebral fissures, should be taken into account in estimat- 

 ing the resemblances and differences with respect toman 

 and t he ot her anthropoids. Possibly these considerations 

 may apply also to the somewhat mooted question as to 

 the extent to which the occipital lobes of the cerebrum 

 project over the cerebellum. Here, however, there enters 



