1888.] NATURAL SCIENCES OF PHILADELPHIA. 99 



the black of the special organ above mentioned. In the tiger's marks, 

 as seen on the mnzzle, they are undoubtedly correlated to the distribu- 

 tion of the infra-orliital nerves. It is probable that similar patches 

 of color, either black or white, are related to similar causes. Among 

 them may be mentioned the black oral angle in Felis onca, the white 

 lips of Tapir pinchaque, and the black lower lip in some varieties 

 of the bull terrier and the fox terrier. In the ground hackie 

 {Tamias striata) I have demonstrated that the main longitudinal 

 body stripe answer to the terminal filaments of the intercostal nerves 

 and to those nerves which are in serial homology with them.^ I have 

 found the spots on the fawn of the Virginian deer ( Cariacus virginia- 

 nus) answer to the ])laces at which the cutaneous nerves pierce the 

 fascia. 



The papilla on the flexor aspect of the fore-arm which is seen in 

 the domestic cat, the sciurmorph and myomorph rodents, and in 

 some of the lemurs, is furnished with bristle-like hairs with the ex- 

 ception of the last named animals. It is supplied by a separate 

 nerve in the domestic cat. The length of the hairs correlate with 

 the length of the vibrissse of the labial set, and are used (as I have 

 observed in the common mouse) for cleansing the face and especially 

 in combinf;: the labial bristle?. J. Bland 8utton '^ found a small 

 bristle-bearing wart on the flexor surface of the the fore-arm in 

 Lemur catta, Ch irogaleus coquerli and Hapalemur griseus. No special 

 pigment patches or hair clumps have been found associated with 

 this papilla. 



The so called "chestnut" of the fore-leg of the horse is probably 

 homologous with this growth. Owing to the changes in the limb 

 coincident with the reduction of the toes the growth assumes a more 

 posterior position. 



All warts and skin caruncles are best developed on the naked 

 spaces at or near the margins of hairy surfaces. They are well seen 

 on the margins of the regions of the whisker and the moustache in 

 the human subject. They are found about the mandibles in the 

 moose {Alces canadensis) and the hog. The same positions are 

 seen occupied by warts in the bat where the face is sj^arsely haired. 

 P. Michelson^ found warts on the margins of the pilose patches in 

 trichosis circumscripta. 



^ Science 1887. 



2 Proc. Zool. Sue. Lond. 1887, 372. 



3 Virchow's Archiv. 1885, C, 66. 



