212 MIMICRY IN N. AMERICAN BUTTERFLIES 



from Dr. Holland an account of the other, believes that the 

 disappearance of the stripe is here part of a general blurring 

 of the colour-scheme in which some elements are obliterated 

 and there is a tendency towards the invasion of one colour-area 

 by another. The extreme varieties captured by Mr. Cook 

 himself, did not, on the other hand, differ at all from the 

 normal archippus except in the absence of the black stripe 

 from the upper surface of the hind wings. To this stripe- 

 less variety Mr. Cook and Mr. Watson have given the name 

 lanthanis. Mr. Cook's accurate data and most of his speci- 

 mens were unfortunately destroyed when the college build- 

 ings at Albany were burnt down on Jan. 6, 1906. It is 

 much to be hoped that he may be able to continue his most 

 interesting observations in this favourable locality, and that 

 naturalists may be stimulated, by these records, now by 

 Mr. Cook's kindness made public for the first time, to work 

 in other North American localities. 



