Contributions to the anatomy of anthropoid apes / by Frank E. Beddard.
- Frank Evers Beddard
- Date:
- 1893
Licence: Public Domain Mark
Credit: Contributions to the anatomy of anthropoid apes / by Frank E. Beddard. Source: Wellcome Collection.
177/246 page 309
![skeleton with which to compare), and have come to the conclusion that the differences between specimens B and C may, provisionally at least, be ascribed to both age and sex. On comparing the caudal vertebrae of a young Galapagos tortoise (T. elephantopus) with those of an adult of a closely allied form (T. vicina) 1‘find the articular facets to be nearly plane in the former, whereas the cup-and-ball system is strongly developed in the latter. As to the anchylosis or non-anchylosis of the costoids, I think the examination of more material would reveal a great amount of individual differences on this point, irrespective of age or sex. Both specimens of T. elephantina show no trace of suture, but I find a great amount of individual variation in other species. In the adult specimen of T. vicina most of the costoids show a distinct suture with the centrum, whilst those of the 6th vertebra, the right one of the 10th, the left of the 16th and 17th, and the right of the 18th and 19th are more or less completely united with the centrum. After describing the tail of the adult male T. elephantina, Dr. Gunther adds:— “Nearly always the animal carries it [the tail] bent sidewards under the carapace, generally towards the left side; and therefore I anticipated to find a want of symmetry in some portion of the root of the tail; however, nothing of the kind can be observed.” This statement is not quite correct. Since the above lines were written, Dr. G. Smets1 has pointed out that the basal caudal vertebrae of T. sulcata and other Land-Tortoises are characterized by a remarkable asymmetry, especially with regard to the zygapo- physes, and I find his statement borne out by the gigantic species as well. Smets remarks of T. sulcata that the right postzygapophysis of the first sacral vertebra is obliterated, whilst the left is well developed; on the second sacral the left zygapophysis is more developed than the right; likewise on the first caudal. On the second caudal the right postzygapophysis is slightly more massive than the left, but its articular facet is smaller; in the 3rd, 4th, and 6th the right postzygapophysis is more developed than the left, whilst in the 6th to 8th it is the reverse. The first and second caudal vertebrse have the diapophyses more developed than the left; on the third vertebra the left diapophysis is less massive but a little longer than the right; fourth and fifth with the left, seventh with the right, diapophysis longest. From the ninth vertebra any striking asymmetry ceases. In the large male specimen described by Gunther2 the second sacral vertebra has but one prezygapophysis, the left; the facet of the right postzygapophysis of the first caudal is much larger than that of the left, but little larger in the second; in the third vertebra the left postzygapophysis is the largest, and in the fourth it is the right. In the female specimen the asymmetry is much less marked. In the 3rd and 4th vertebrse of specimen A of T. grandidieri the right postzygapo- physis is more developed than the left, in the 6th the left. In specimen B the left postzygapophysial facet of the second sacral is much higher 1 Museon, 1887, p. 394. 2 Op. tit. p. 29.](https://iiif.wellcomecollection.org/image/b28141386_0177.jp2/full/800%2C/0/default.jpg)
