556 SCIENCE PROGRESS. 



men of Argynnis adippe were captured having the silver 

 spots on the underside of the hind wing absent we should 

 call it an extraordinary sport ; but in most subalpine locali- 

 ties such specimens are common both in A. adippe and A. 

 niobe. In the latter species in fact it is the silver-spotted 

 form which is exceptional in many localities. 



In any extended view of variation it is soon apparent 

 that a variety which in one species and one locality is 

 exceptional, may in another species or another locality be 

 of constant occurrence. 



So also in regard to the reiterated assertion that the 

 appearance of discontinuity between type and variety is 

 due to the arbitrary rejection of intermediate forms. It is 

 true enough that in very few cases are proper statistics 

 forthcoming, and that as yet it is impossible to say how 

 imich discontinuity exists in any but a few examples. 

 Nevertheless the fact that in innumerable cases the type 

 is common, and a variety is common relatively to the in- 

 termediate forms is familiarly known to collectors. Every- 

 thing depends on the species and the variety chosen for 

 illustration. For example, in the moth Calliniorpha hcra 

 the hind wings are generally red, but a yellow variety 

 is common. In this species it happens that specimens of 

 intermediate tints shading through orange and buff are 

 frequent. So far as I know it has not been established 

 statistically that the intermediates are less common than 

 the yellow variety, and possibly enough they are more 

 common. But in Thais medesicaste the discontinuity be- 

 tween the type and the variety honoratii found flying with 

 it at Digne, in which the yellow of several cells wings 

 is replaced by red, cannot be questioned. The inter- 

 mediate forms are either absent or quite exceptional, though 

 type and variety occur together.^ 



The further we proceed in the study of variation the 

 clearer it becomes that we have no warrant for applying the 

 conclusions as to variation and inheritance derived from the 



1 In illustration of the want of blending in this case it may be men- 

 tioned that a specimen was reared by Standfuss ((8), p. 319) which was 

 honoratii on the right side and medesicaste on the left. 



