FIELD AND FOREST. 77 



of disposing of their dead seems to be the best that could be devised 

 by any people. 



It is the custom among the Yumas, when a rich man dies, to kill all 

 of his horses, and eat them for baked meats. All that he may possess 

 is placed upon the funeral pile and consumed with his body. ' ' 



Asymmetrical Coloration in Feral Animals. 



In an interesting "Note on Color Variation in Mammals," * Mr. 

 J. A. Ryder has called attention to the fact of asymmetry of coloration 

 so often observed among our domesticated animals, as the horse, ox, dog 

 and cat, and also in rabbits, Guinea pigs, goats, swine, &c, contrasting 

 it with the symmetrically disposed color areas in feral animals even 

 where they depart from the normal states of coloration for the species. 



Thus Mr. Ryder cites instances among hares, mice and deer in 

 which, in a wild state, white areas occuring, in partial albinos are sym- 

 metrically disposed on the two sides of the body, and states that he 

 never met with an instance in which such white areas were not thus 

 symmetrically arranged. In summarizing the facts observed by him 

 he formulates the following : 



i. " That bilateral symmetry is interfered with in some way by do- 

 mestication. 



2. That where variation in color takes place in feral animals, they 

 are invariably, so far as observed, symmetrically colored. 



3. That it is possible that the degree of asymmetry is an indication 

 of the length of time domestication has been operative. ' ' 



As my experience happens to be somewhat different from Mr. Ry- 

 der's I offer the following as a further contribution to the subject. In 

 a specimen of Arvicola riparius more than half white, which came 

 into my hands some years since, the white areas were not only very 

 irregular, but were quite unlike on the two sides of the median line of 

 the body. I have also noticed in two species of Mexican squirrels 

 (Scuirus boothice and S. hypopyrrhus ) white spots disposed very irreg- 

 ularly and unsymmetrically, and in the latter black markings also un- 

 symmetrically disposed. One specimen of S. hypopyrrhus, for example, 

 had one fore limb wholly white from the elbow nearly to the end of 



* Proc. Acad. Nat. Sci. Phila., 1877, pp. 272-27 j. 



