184 INITIATIVE IN EVOLUTION 



This example of a still-born, but otherwise normal infant 

 illustrates well the previous statement that certain bursae are 

 congenital and others of less functional importance are formed 

 after birth. Whereas the olecranon, wrist, patellar, ankle and 

 tendo achillis bursas are fully formed, those under the acromion 

 processes, one of those of the condyles of the femur, and the digits 

 of the hand, those ever the superior anterior spines of the ilium 

 and those of the foot are little if at all developed in this case. 



Another still-born child at seven months was also dissected 

 and this had well-formed prepatellar bursas, scanty ones over the 

 olecranon processes, also over the small joints of the hand and 

 foot where they were difficult to isolate and over the malleoli they 

 were only slightly developed. 



A foetus in spirit I examined and found no commencement of a 

 prepatellar bursa. 



Examination of Living Primates. 

 Anthropoid Apes. 



Eight of these I examined during life at the London Zoological 

 Society's gardens in 1908, four chimpanzees, two orangs and two 

 gibbons. These afforded the opportunity of ascertaining by means 

 of touch the presence, and in a minor degree the size and efficiency 

 of the main subcutaneous bursa, just as one can do this in a human 

 subject. The chimpanzees were A, aged thirteen ; B, aged seven ; 

 C, aged three ; and D, aged two -and -a -half years ; the orangs E, 

 aged thirteen ; F, aged three years ; the gibbons G and H both 

 two to three years. 



These eight specimens possessed good examples of the leading 

 subcutaneous bursas over the olecranon process, the styloid process 

 of the ulna, the patella and both malleoli . 



The smaller and less definite bursas gave the following 

 results. 



Chimpanzees. 



A. Hand. Bursas on all the metacarpal and first phalangeal 



joints ; none on the second phalangeal joints of 

 D 2, 3, 4, 5. 

 Foot. Bursas well marked on the five metatarsal first 

 phalangeal joints ; none on D 2, 3, 4, 5 joints, 

 but one on that of D I . None found on second 

 row of phalangeal joints. 



B. Moderate development of bursas on metacarpo-and meta- 



tarso-phalangeal joints of D 1 ; doubtful on those of 

 D 2, 3, 4, 5. 



