94 PROCEEDINGS OF THE ACADEMY OF • [1888. 



effort to extend a fold of skin from the sides of the limb. A skin- 

 fold is demonstratable in 3Ienopovia (where it is supplied by a 

 branch of a nei*ve) as well as in Ernys and its allies. It is the be- 

 ginning of the hair-covered membrane in the flying squirrel {Sciur- 

 opterus) and in Belideus; it is enormously disj)layed in the bat. 



The long fringe on the ulnar border of the fore-arm in the setter 

 dog may be named as an example of its occurrence in a terrestrial 

 mammal. 



The fold corresponding to it is not so evident in the hind leg — 

 where it would naturally be sought for on the inner border. The 

 line of feathers seen in some varieties of the pigeon and of the domes- 

 tic fowl on the outer border of the leg may be associated with a 

 similar proclivity to that above named. 



In a case of trichosis circumscripta recorded by B. Ornstein^ in an 

 adult male a growth of hairs was found on the ulnar border of the 

 fore-arm of both sides. 



In some species of Quadrumana the hair of the arm and the fore- 

 arm inclines tow'ard the elbow. Wallace'^ and Darwin^ describe this 

 arrangement in connection with the use made of it by t^e animal in 

 shedding the water falling upon the flexed limb. That the hair in 

 Hylobates agilis should be directed toward the wrist is evidently an 

 aberrant arrangement if we are to follow the distribution of the 

 lanugo as outlined by Eschricht and Voigt. 



A marked instance of growth of the hair from ulnar border of the 

 fore-arm and the corresponding border of the arm is met wdth in 

 Propithecus verreauxii-coquerelii.^ A long brilliant fringe of orange 

 and white colors equals in width the arm at its greatest diameter. 



The Axilla and Pudenda. — The presence of hair in the axilla and 

 pudenda in man is not without interest in connection with the pilose 

 regions of the newly born infant. It will be noticed that both Esch- 

 richt and Voigt separated the pudenda and the entire perineum from 

 the rest of the body. 



In Lemur varius^ the prevalent color being a light brown the per- 

 ineum is black. The axilla is often of the same color as the inside 

 of the entire fore-leg in Indris brevicaudatus.^ 



1 Arch. f. Antliropologie, 1S6G, 507. 



2 On Natural Sekclion, 344. 



3 On Descent of Man. Am. Ed. I. 1S5. 

 * Am. Mus. No. 973. 



5 Ibid. No. 268. 



6 Ibid. No. 260. * 



