378 



Mr Appleton, The Influence of Function 



But reversion to slow-moving habits will no more resuscitate an 

 absent muscle than a lost third trochanter. 



The adductor group of musculature (with which must be con- 

 sidered the MM. semimembranosus and caudofemorahs [Leche] 

 from their frequent synergism) shows important modifications 

 characteristic of various speciahsations. 



Attached in the primitive type along the whole femoral shaft 

 and down to the head of the tibia, the bulk of this musculature in 

 cursorials comes to be concentrated in the region of the knee. The 

 value of this will be pointed out subsequently. At the same time 

 it shows great increase in size. 



Carnivora deviate far less from the primitive type than do 

 Artiodactyla and Perissodactyla, though the speciahsed types, 

 such as Canidae, show great increase in size of the adductors. 



Table I. Weight* of Adductor Group Musculaturef 

 (including Semimembranosus). 



1 Approximate. 



It is seen that there is a reduction in the adductor musculature attached to the 

 shaft in just those specialised types, cursorials and saltatorials, which exhibit the 

 specialised f emorococcygeus ; but that the total mass may become verj^ large, as in 

 the horse, dog (and lion). The adductor mass in the gorilla is also of great size. A 

 resemblance of the baboon to the cursorials is noticeable in this as in other respects. 



* Unit of weight is M. rectus femoris; the best unit yet found for comparative 

 purposes; little affected by specialisation, and containing a factor depending on 

 femoral length. 



t Muscles concerned: all adductors, pectineus, presemimembranosus (ischio- 

 condyloideus), semimembranosus, caudofemoralis. 



% Includes condylar part of adductor magnus. The figures of Dursy for the adult 

 are similar. 



§ The rectus femoris is exceptionally small (partly replaced in function by 

 tensor fasciae femoris). 



