1888.] NATURAL SCIENCES OF PHILADELPHIA. 87 



The transverse body stripes are the highest form of development of 

 a body-mark, and succeeds in phylogeny the series of dotted-marks. 

 This order is the reverse of that suggested by Darwin. A paper by 

 G. T. Rope' describes two varieties of coloring in the English form 

 of the domestic cat viz : transverse stripes or rows of dots on a white 

 ground and white markings of a more or less longitudinal direction 

 on a black ground. 



The following list includes the arrangement of the subject-matter 

 of the present essay. 



1. The " break " from the prevailing or ground color compared 

 with the positions at which hair is retained in nearly hairless animals. 



2. Briudles. 



3. The regions in which color-marks are found regularly disposed. 

 These are : the dorsal line of the trunk ; the back of the neck ; the 

 the dorsi-facial line ; the ventre and limbs ; the ulnar border of the 

 foreleg ; the axilla and pudenda ; the "collar;" the regions of the spe- 

 cial senses ; the sides of the body ; the regions of nerve-endings ;; 

 nuiscle-regions ; regions which are rich in seba and moisture. 



4. The effects of age. 



5. Bilaterality. 



6. Antero-posterior symmetry. 



1. The "Break" from the ground Color, or prevalent 

 Color, compared avith the Positions at which Hair is re- 

 tained IN NEARLESS HAIRLESS Animals. — When an animal of 

 a single color changes (even in a slight degree) the uniformity of 

 the tint, the new color will appear in an order definite enough 

 for the variety, species, and sometimes for the family to which 

 the animal belongs. A black, gray or chestnut colored dog when 

 thus changing almost invariably has a white spot appear at one of 

 the following localities : The tip of the tail,^ the breast, the dorsal 

 surfaces of the feet, and the tips of the ears. I have observed these 

 changes in the New Foundland dog, the greyhound, the Irish setter 

 and the collie. In the sunbear ( Ursus malayanus) the prevailing 

 black is relieved by a crescentic whitish-yellow spot on the breast. 

 Sarcophilus when varying from its prevalent color exhibits a spot of 

 white in the same region. Horses having white feet and a white 



1 Zoolagist, 1881,353. 



* According to Gervais the first white appears at the tip of the tail. G. T. 

 Rope (Zoologist, 1881, 353) states that where only a very minute portion of white 

 occurs, it is most likely to be found on the chest. 



