470 Mr Ap2)leto7i, The Gluteal Region of Tarsius sjyectmm 



The similarity of Lemur and Tupaia (except as to the gluteus 

 medius) is noteworthy. In Tarsius the caudofemoralis is large, 

 while the gluteus medius and quadratus femoralis are little de- 

 veloped. 



Table II. 



Actual weights of thigh muscles (supplied from lumbar plexus) in a 

 spirit specimen of Tarsius — and of certain shank muscles. 



'^' -< a O tD.^: X w n^ PL, pj^ f> > 5 

 Actual weights) i.» „,„ ,_ „„ „_ ,, ,„ „ 



ingrains / ^^ ^^ ^^ ^'^ 3-o 1-4 18 29 51-2 16-5 9-0 5-4 18 



It Mdll be noticed that the hip extensors of Tarsius are not 

 developed to the huge extent of the quadriceps extensor. Their 

 weight compared with that of the quadriceps is in the ratio 1/5|, 



VIZ 



Gluteus medius ^ 



Femorococcygeus I , . ^ . ^ -, 



Caudofemoralis f ^^'^ grains. Quadriceps extensor 79-6 grains. 



Adductor magnus 



J 



Now this ratio shows curiously little variation among Mammalia. 

 It is convenient for the present purpose to employ the same set of 

 four hip- extensors [it would, therefore, prove of very doubtful 

 utility in comparisons with Sauropsida or Monotremes (see also 

 footnote % p. 471)]. 



In the less specialized forms the ratio as thus defined of 

 hip extensors . 

 knee extensors ^^ ^^^^^r less than unity. It tends to rise somewhat 



in certain cursorial groups, viz. Artiodactyls and Perissodactyls. 



A large leaping animal like the Kangaroo shows no marked 

 disturbance of this ratio. And while the ratio in Lemur resembles 

 that of most Mammaha, it is found in Tarsius to be extraordinarilv 

 small. 



