THE AMERICAN NATURALIST [Vol. XLVIII 



the primary patches, to be considered under the cow, is 

 not a wholly similar phenomenon. 



Five diagrams illustrating the domestic cat are shown 

 in Figs. 16 to 20, and are interesting to contrast with 



those of the dog, also a carnivorous mammal. The 

 demarcation of the primary patches is usually less sharp 

 than in dogs, but is in general similar. The most common 

 appearance is where the primary breaks occur in the 

 mid-line below, giving a white throat, chest or belly; or 

 the separation of the aural centers produces a white 

 streak on the nose or extends it up between the ears. 

 The ear patches in Figs. 17, 19, 20, show successive reduc- 

 tion, so that at first the hinder margin of the ears, as in 

 dogs, becomes white, then with further decrease in pig- 

 ment production, the inner bases only are colored. The 

 neck patch has its ultimate center farther back than in 

 dogs so that when much reduced, it is present as a pig- 

 mented spot at the very base of the neck or even at the 

 front of the shoulder (Figs. 16, 17). In Fig. 16 the neck 

 patch of the right-hand side is only slightly reduced and 

 is in contact anteriorly with the ear patch, while poste- 



