474 Mr Applefon, The Gluteal Region of Tarsius sj^ectruin 



this does not appear to be necessary. For this musculature in 

 jumping animals other than Tarsius, and the Kangaroo, verification 

 is needed. 



(2) Attachment of muscles to tuber ischii instead of to tail. 



In Reptilia and Insectivora, both femorococcygeus and caudo- 

 femorahs (or their precursors) are attached to caudal vertebrae. 

 But in two Insectivora Macroscelides and Erinaceus), one of them 

 a jumper, the femorococcygeus is recorded as attached to the tuber 

 ischii. A new type of hip-extensor is produced, acting as far from 

 the hip-joint as possible, and therefore exerting the greater leverage. 



The same principle is seen in cursorial types where the long 

 vastus (= gluteus maximus +? femorococcygeus) gains attach- 

 ment to the tuber ischii, while at the same time the tuber ischii 

 shifts away from the hip- joint downwards and backwards (Artio- 

 dactyla). 



In Tarsius it is the caudofemorahs alone which gains an ischial \ 

 attachment; but in giant apes we see the femorococcygeus attached \ 

 here. An ischial attachment for hip-extensors appears to be no \ 

 prerogative of jumpers, but is shared alike by the active Metatheria 

 and cursorial Eutheria, and also by the giant apes. 



To sum up, Tarsius exhibits, in the musculature of the gluteal 

 region, primitive features hke the genus Lemur, recalling Tupaia 

 and Hijpsiprymnodon, and less closely reproducing the conditions 

 of Monotremes and Reptiles. Along with these features we find 

 certain modifications, such as the ischial attachment and develop- 

 ment of the caudofemorahs, in which Tarsius has progressed beyond 

 the conditions in Lemur and is paralleled by many Marsupialia. 

 Its small size is held accountable for a certain lack of parallehsm 

 between Tarsius and the Kangaroo. 



While certain of the primitive features of Tarsius and Lemur are 

 lost in Simiidae, others, such as a well developed femorococcygeus. 

 are retained in the latter. 



