102 PROCEEDIXGS OF THE ACADEMY OF [1888, 



Avhite feet. In- a word the fawn gray of adult life turns to white in 

 the same regions (with the exception of the tip of the tail and the tip 

 of the ear) that an animal is apt to break from its prevalent color. 

 (See p. 88) 



The loss of hair from the crown in man is the loss of tlie dorsal 

 part of the "collar" of the Quadrumana as already mentioned on 

 p. 95. 



The growth of the hair from the tragus in man is more decided in 

 middle life than at an earlier period and turns gray at a later period 

 than the whisker. 



5. BiLATERALiTY. The study of color marks in connection 

 Avith the law of asymmetry yields many attractive results. Prof. 

 Wm. H. Brewer^ found the white marks on the feet of horses more 

 developed on the left than the right side. In Nyctipithecus I have 

 found the left supra-orbital region white, and a white spot detected 

 on the left cheek, while the remainder of the fur was gray. H. 

 Ranke'' describes a case of trichosis circximscripta in which a pilose 

 patch was seen on the left cheek in advance of the region of the 

 whisker but none corresponding to it on the right. The left arm, 

 according to R. Hilbert,^ may be alone pilose and a patch of icthyosis 

 be confined to the shoulder of the same side. Dr. Henry H. Donald- 

 son found as the result of many observations on the human subject 

 in the south of Germany, the wart on the nasio-labial groove 

 to be much more frequent on the left than the right side. He 

 found a similar disposition in numbers of engraved portraits of 

 distinguished men of all nationalities. I have frequently found the 

 black circumpalpebral patch in the fox-terrier and the bull-terrier 

 confined to the left side, or when the patches are found on both sides 

 the left patch to be the larger. According to W. H. Flower* the 

 color-marks of Lycaon are remarkable for being different on the two 

 sides of the body. Prof Brewer states^ that in man the beard com- 

 monly turns gray first on the left side. It cannot be a coincidence 

 that the left side in all the above instances shows the greatest disposi- 

 tion to variation. I have found a similar disposition to exist in the 

 antlers of the Virginian deer. 



^ Proc. Am. Assn_ for Advancement of Science ISSl, XXX, 246. 



2 Archiv. f. Anthropologie 1883, XIV, 339. 



3 Virchow's Archiv.1885, XCIX, 569. 



* Article " Mammalia" British Encyclopedia, IX edition. 

 5 1. c. 249. 



