36 READINGS IN BIOLOGICAL SCIENCE 



The Gorilla's brain-case is smaller, its trunk larger, its lower limbs shorter, 

 its upper limbs longer in proportion than those of Alan. 



I find that the vertebral column of a full grown Gorilla, in the Museum 

 of the Royal College of Surgeons, measures 27 inches along its anterior 

 curvature, from the upper edge of the atlas, or first vertebra of the neck, 

 to the lower extremity of the sacrum; that the arm, without the hand, is 

 3 1 1/2 inches long; that the leg, without the foot, is 26V2 inches long; that 

 the hand is ()% inches long; the foot 1 1^ inches long. 



In other words, taking the length of the spinal column as 100, the arm 

 equals 1 15, the leg 96, the hand 36, and the foot 41. 



In the skeleton of a male Bosjesman, in the same collection, the propor- 

 tions, by the same measurement, to the spinal column, taken as 100, are 

 — the arm 78, the leg 1 10, the hand 26, and the foot 32. In a woman of the 

 same race the arm is 83, and the leg 120, the hand and foot remaining the 

 same. In a European skeleton I find the arm to be 80, the leg 1 17, the hand 

 26, the foot 35. 



Thus the leg is not so different as it looks at first sight, in its proportions 

 to the spine in the Gorilla and in the Man — being very slightly shorter 

 than the spine in the former, and between Yk, and % longer than the spine 

 in the latter. The foot is longer and the hand much longer in the Gorilla; 

 but the great difference is caused by the arms, which are very much longer 

 than the spine in the Gorilla, very much shorter than the spine in the Man. 



The question now arises how are the other Apes related to the Gorilla 

 in these respects — taking the length of the spine, measured in the same 

 way, at 100. In an adult Chimpanzee, the arm is only 96, the leg 90, the 

 hand 43, the foot 39 — so that the hand and the leg depart more from the 

 human proportion and the arm less, while the foot is about the same as in 

 the Gorilla. 



In the Orang, the arms are very much longer than in the Gorilla (122), 

 while the legs are shorter (88); the foot is longer than the hand (52 and 

 48), and both are much longer in proportion to the spine. 



In the other man-like Apes again, the Gibbons, these proportions are 

 still further altered; the length of the arms being to that of the spinal 

 column as 19 to 11; while the legs are also a third longer than the spinal 

 column, so as to be longer than in Man, instead of shorter. The hand is 

 half as long as the spinal column, and the foot, shorter than the hand, is 

 about %iths of the length of the spinal column. 



Thus Hylobates is as much longer in the arms than the Gorilla, as the 

 Gorilla is longer in the arms than Man; while, on the other hand, it is as 

 much longer in the legs than the Man, as the Man is longer in the legs than 

 the Gorilla, so that it contains within itself the extremest deviations from 

 the average length of both pairs of limbs. 



The Mandrill presents a middle condition, the arms and legs being nearly 

 equal in length, and both being shorter than the spinal column; while hand 



