SOCIETY OF THE UNIVERSITY OF ABERDEEN. 



145 



Interossei. 



There were four dorsal interossei and five palmar, the basal line 

 of abduction and adduction being, as in man, the middle digit. 

 Champneys counted six palmar interossei. It must be noted, how- 

 ever, that of the five interossei seen from the palmar surface only 

 three are adductors proper. 



The two accessory muscles are united at origin, but their tendons 

 pass to adjacent sides of middle and ring fingers, so that one may be 

 considered an accessory adductor while the other is really an abductor. 

 Hepburn, in discussing these accessory interossei, takes the view that 

 they are properly to be considered as accessory slips to the dorsal 

 interossei. 



Vide also Cunningham on the " Dorsal Interosseous Muscles of 

 Thylacinus Cynocephalus ". Journal of Anatomy and Physiology, 

 1878. 



MUSCLES OF THE LOWER EXTREMITY. 



Tensor vagina femoris. 



Arose from an aponeurosis common to it and the gluteus medius 

 and minimus externally and the fascia separating it from the trans- 

 versalis internally. Its origin reaches nearly to the anterior superior 

 spine and its posterior border is associated with the fascia covering 

 the gluteus medius. The muscle is thin and about ^ of an inch 

 in breadth. Its insertion is into the fascia lata of thigh where its 

 fibres intersect with those fibres of the gluteus maximus which are 

 also inserted into the fascia lata. 



Gluteus maximus. 



Compared with the same muscle in man this muscle is of very 

 insignificant size in the chimpanzee. It arose from an aponeurosis 

 common to it and the gluteus medius and covering the outer surface 

 of the latter muscle. This aponeurosis extended from the crest of the 

 ilium down to the tuberosity of the ischium. It is a relatively thin 

 muscle, especially in its upper part, and the muscular fibres do not 



reach higher than the level of the sacro-sciatic notch. The lower part 



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