482 Prof. E. B. Poulton on the Mimetic N. American 



inlorquini than in weidemeyeri. Tlie study of its relative 

 development in the southern part of the range would 

 require a much larger number of specimens than I have 

 as yet had the opportunity of seeing. There is however 

 no doubt that the feature is generally suppressed in 

 Vancouver's Island and that it is usually well developed 

 in British Columbia. 



The undoubted affinity between californica and lorquini 

 may lead naturalists to conclude that their resemblance is 

 due to relationship and not to mimetic approach. It is 

 commonly forgotten that mimicry, being indepe^ident of 

 affinity, occurs between forms of all degrees of relationship, 

 the closest as well as the most remote. When the chief 

 mimetic element in the pattern of Icn^quini is examined it 

 is at once apparent that the likeness is superficial, and 

 that the appearance is produced in a manner entirely 

 different from that of the model. The orange patch on 

 the fore-wing of californica is a clearly defined sub-apical 

 and submarginal marking, roughly resembled in the mimic, 

 lorquini, by the inward growth of a brown marginal mark- 

 ing (compare Figs. 2 and 3 with 6, 7 and 8 on Plate XXV). 

 There can be little doubt also that the cream tint of 

 lorg^dni is not ancestral, but due to recent modification of 

 white markings like those of iveideraeyeri, arthemis and 

 many Palaearctic species of Zimenitis. The average 

 increase of mimetic likeness in the area occupied by the 

 model confirms in the most convincing manner the con- 

 clusion that the resemblance is due to mimicry and not to 

 affinity. 



Differences between californica and bredowi are 

 SUCH as to promote a resemblance between the 

 northern form and lorquini. 



a. The shape of the wings. — The marked difference in 

 the shape of the wings between the males of the northern 

 califurnica and the southern hrcdovn is well seen by com- 

 paring Figs. 2 and 3 with 4, 5, and 9 on Plate XXV. 

 This distinction, apparently, does not hold in the other 

 sex; for the few southern females I have seen exhibited 

 the proportions of the northern form. The difference 

 was clearly explained, although without reference to the 

 females, by A. G. Butler in his original description of cali- 

 fornica (Proc. Zool. Soc. Lond., 18G5, p. 486): — " the wings 



