EEVISION OF THE KING SNAKES. 99 



forniae, or its aberrant representatives, (2) typical californiae is 

 found only south of Los Angeles County, (3) in San Diego County 

 all the individuals are typical, (4) in Riverside Coiuity some are 

 typical and some partly aberrant, and (5) north of Riverside County 

 all are aberrant. 



The specific identity of this form has been often questioned on 

 account of (a) its identity in structural features with hoylii, (b) the 

 remarkable variation in its pattern and its evident approach in these 

 variations to the pattern of hoylii, (c) its alleged rarity and apparently 

 sporadic distribution, (d) its occurrence wholly within the range of 

 its nearest relative. 



In support of its specific identity it may be remarked that (a) 

 color pattern differences alone are often used in the differentiation 

 of species, (b) There can be no doubt of its approach in pattern to 

 hoylii in the northern portion of its range, but tyi^ical hoylii occurs 

 here while typical californiae does not, indicating that this is not an 

 instance of intergradation ; and in the southern part of the range, 

 both forms are common in the same localities and no aberrantly 

 marked individuals are found. If interbreeding produces aberrant 

 individuals, why is californiae not found in typical form in Fresno 

 County, if hoylii is; and if interbreeding takes place in San Diego 

 County and Mendelian segregation is to explain the occurrence here 

 of only the typical patterns of both forms, why should aberrant 

 patterns be found in some other portion of the range ? (c) Its rarity 

 in the region of its typical development is not apparent; where it 

 does seem to be rare it is variable, (d) The fact of its range lying 

 whoUy within that of its nearest relative is an unusual instance and 

 in need of explanation. 



Affinities. — As brought out in the discussion of variation, the 

 affinities of this form are all with hoylii. The only other member of 

 the getulus group which ranges anywhere near californiae is yumensis. 

 To assume yumensis to be the ancestor of californiae raises a question 

 more difficult to answer than the one raised by assuming hoylii to be 

 the ancestor. It would then have to be explained how one species 

 gave rise to two other species, which occupied the same region to- 

 gether, in competition, and both survived. Yumensis is however, 

 excluded from direct relationship by the fact that the only region 

 where its range is near that of hoylii is the region where californiae is 

 constant in its specific characters, and by the fact that the abberra- 

 tions of californiae are toward hoylii and are in a region that could 

 never have been occupied by yumensis. 



We have then the peculiar condition of a species being differen- 

 tiated within the range of its parent. If we say it is a mutation, 

 we must explain why it is constant in pattern in the southern portion 



