o4() Vniversitjj of CaUfornia PuhJlcatiovs in Zoalogi/ [Vol. 21 



environment to which other carnivores are sensitive ; and we find it 

 present under surprising!}^ different sets of conditions. We have 

 captured it among the desert shrubbery at 178 feet below sea level on 

 the floor of Death Valley, where the summer temperature is probably 

 higher than at any other point in the Southwest ; and we have taken it 

 at an altitude of 11,000 feet, close to timber line at Cottonwood Lates 

 near Mount Whitney ; we have found it common along the Colorado 

 River bottom near Yuma, among the yuccas on the Mohave Desert 

 near Victorville, and in tlie humid forests of Humboldt Bay. 



This fact, of the practically uninterrupted extent of the wildcat's 

 range throughout the state, may be offered in explanation of our con- 

 clusion that, instead of two or more distinct species of wildcats existing 

 within the state, as heretofore generally supposed, there is but one 

 species, with several completely intergradient subspecies or geographic 

 races each occupying one of the main faunal divisions of the state 

 (see map, fig. A). There are within our confines no barriers or 

 interruptions of occurrence such as would help to make distinct species. 



The material forming the basis of our present study is as follows : 

 In the Museum of Vertebrate Zoolog3% 117 specimens (skins-with- 

 skulls or skulls only) from California, 12 from Nevada, and 11 from 

 Arizona ; loaned us by the United States Biological Survey, Washing- 

 ton, through its Chief, Dr. E. W. Nelson, 13 specimens from Wyoming, 

 Utah, Oregon, Washington, AVest Virginia, and New Hampshire; 

 and loaned us bj^ the Museum of Comparative Zoology, Cambridge, 

 through its Director, Mr. Samuel Henshaw, 3 specimens, one (the 

 type of Lynx fasciatus ocidcus Bangs) from California, and two from 

 British Columbia. Total, 156 specimens. 



The assembling of the series specified has brought out a principle 

 which has become apparent over and over again under similar cir- 

 cumstances, namely, that the larger the number of specimens of a 

 species or subspecies available for examination, the wider the range of 

 variation manifest in the characters of that form. The wildcat seems 

 to be particularly subject to individual variation ; and to deteraiine 

 what is the true nature of the geographic variation (that sort of varia- 

 tion which we look upon as significant of incipient phylogenesis) is 

 possible only upon the basis of considerable material from each of many 

 small areas. AVhile our present material is not ideally abundant, it 

 /m.s proved sufficient to convince us that, as intimated above, all the 

 racial types in California are confluent. 



The main features of the wildcat which exhibit variations of an 

 easily appreciable kind are as follows : general size, relative size of ear, 



