190: 



CARPAL VIBKISS/E IN MAMMALS. 



131 



possession of this tuft of vibrissfe. Its presence is not, however, 

 universal in this order of mammals. On the whole, 1 should be 

 disposed to think that those Rodents whose feet have more of an 

 Ungulate character, such as the Capybara and Bolichotis, are 

 without the structure in question ; but the majority of the genera 

 which I have examined certainly are furnished with these long 

 vibrissre. I have found them, for example, in several species of 

 Sciurus, in Cricetus, Gerhillus, Mic7'otus, Saccostomios, Acomys, 

 Mus, and Pteromys. It is remarkable that though they exist in 



Text-fij?. 19, 



Right liiiiil foot of Petaurus seiureus ; lateral surface. 

 H, tuft of vibrissai. 



the Flying- Squirrel just mentioned, and I have had the oppor- 

 tunity of verifying their occurrence in two species, they are 

 totally absent from the wrist of another genus of Flying- Squirrel, 

 viz. Sciuropterus. Nor can I find the tuft in the Jerboa or in 

 Rhizomys. 



Another peculiarity of this tuft of specialized hairs is that it is 

 not invariably to be found in all individuals of a given anima,l. 

 As a rule, so far as my experience goes, it is the case that the tuft 

 is constant and to both sexes. But in the Suricate I have found 



