182 INITIATIVE IN EVOLUTION 



(d) Sometimes a third or deep subfascial bursa. 



" These bursse over the knee-joint appear in fcetal life and 

 vary in size in persons of different occupations, being 

 often large in housemaids and carpet-nailers, and 

 often communicating with each other." 1 



(e) Occasionally the upper part of the synovial pouch of the 

 knee-joint is shut off from the general cavity and forms a 

 separate bursa beneath the extensor muscles. It always 

 communicates with the knee-joint though originating 

 independently. 



In the Ham. 



(a) Large bursa between the inner condyle of the femur and 



the gastrocnemius muscle, often opening into the joint. 



(b) A smaller one on the outer side. 



(c) One between the biceps tendon and the external lateral 



ligament. 



(d) One between the semimembranosus 



(e) One between the popliteus 



(f) One between the sartorius }- and the bone. 



(g) One between the gracilis 

 (h) One between the semitendinosus 



Tibia. 



(a) One over the tuberosity. 



Ankle. 



(a) Over both malleoli. 



(b) Between the tendo achillis and the os caleis. 



Foot. 



(a) Over plantar surface of the great toe. 



(b) Over plantar surface of the little toe. 



(c) Over the dorsal surfaces of all the phalangeal joints of the 



toes. 



(d) Over the dorsal surface of metatarso-phalangeal joint of 

 the great toe. 



(e) Over the plantar surfaces of the metatarso-phalangeal 

 joints of all the toes. 



I calculate that there are at least fifty-two separate bursas 

 (about one hundred on the two sides of the body) in the normal 

 or fully developed state, though of these many will be found either 

 absent or with very little of the full structure of a bursa. One small 

 but significant point may be referred to here. We are all familiar 



1 Macalister, p. 488. 



