794 



increases in a greater degree in the Gorilla ; the pleurapophysial part of that process diverges 

 more from the diapophysis, is hroader and more produced than in Man ; the zygapophyses 

 are larger, but the centrum is still narrower ; the neural spine is still very long and very 

 strong, but is somewhat shorter than in the antecedent vertebra. 



The dorsal vertebrae, besides their increase of number the thirteenth however answering 

 to the first lumbar in Man, with the pleurapophyses retained as distinct elements differ in 

 the greater length of the spines of the first five vertebrae, which progressively decrease to the 

 length they present in the Human subject, but with greater thickness, and in the last three 

 with greater antero-posterior extent. The bodies of the middle dorsal vertebrae are shorter 

 in proportion to their breadth ; the diapophyses are thicker, stand more directly outwards, 

 and the costal surfaces are more concave and oblong ; the metapophysis which projects 

 distinctly in the eleventh vertebra in Man, does not so appear until the twelfth in the Go- 

 rilla. In the first dorsal the centrum is larger vertically, and the spine is twice the length 

 of that in Man ; the zygapophyses are larger than in Man ; the costal surface is more pro- 

 duced in the side of the body : but the chief difference is in the position and direction of the 

 diapophysis, which in the Gorilla projects directly outwards below the level of the anterior 

 zygapophysis ; the fore part of the base of the neurapophysis is less deeply grooved in the 

 Gorilla. In the second vertebra of the back the spine is still much longer and stronger ; the 

 diapophysis is thicker, shorter, and more directly extended outwards ; the anterior zygapo- 

 physes are more produced ; the neural canal is rather narrower. The same general differ- 

 ences may be noticed in the three succeeding dorsal vertebrae, except that the spine becomes 

 shorter and the centrum larger in the Gorilla ; the neural arch rises more abruptly beyond 

 the anterior zygapophysis. In the sixth dorsal vertebra the neural spine is reduced to the 

 same length as in the corresponding spine in Man ; the centrum is larger, the neural canal 

 of the same size, the posterior costal pits are longer, the diapophyses still stand out more 

 transversely. In the Gorilla the proportionate increase of the centrum is greater than 

 in Man ; the neural spine is less obliquely bent backwards, and is thicker antero-posteriorly, 

 though not longer ; the anterior zygapophyses are more produced ; the diapophyses are 

 broader and somewhat shorter. In the eleventh dorsal vertebra of the Gorilla the neural 

 spine is much expanded at its extremity. In the twelfth, there are distinct and well- 

 developed metapophyses, projecting from the fore part of the diapophyses, and overhanging 

 the anterior zygapophyses : this vertebra corresponds in this character with the eleventh of 

 the Human subject. The neural spine is broader and thicker, especially superiorly ; there 

 is but one costal surface on each side ; the diapophyses are reduced in size, the metapophyses 

 equalling them, the body and neural spine increasing. 



The thoracic ribs are longer and thicker, more convex on their inner side, with the sub- 

 costal groove not defined, except in two or three of the longest ribs near their vertebral end ; 

 the neck is shorter and thicker than in Man ; the longest rib is one foot four inches in 

 length, that of the longest rib in an average-sized man being thirteen inches. The first 

 rib in the Gorilla is broader in proportion to its length ; the neck especially is shorter and 

 broader, and the body of the rib is less curved than in Man. 



The manubrium sterni is much broader than in Man, and less deeply excavated for the 

 clavicles ; the synchondrosal surface for the succeeding sternal bone is broader, but much less 

 thick than in Man. 



