THE CANADIAN ENTOMOLOGIST. 03- 



I believe that the most expert Entomologist would pronounce the- 

 Anticosti pJiilodicc different in habit from those found in the vicinity of 

 Canadian cities. There appears to be a difference of opinion among 

 Entomologists in reference to the variations in this insect. Mr. Edwards, 

 of West Virginia, says : '* I suspect that at least two species are passing 

 " under the name of Colias ^/li/odice. The species is known to vary 

 '' widely, but some of the supposed varieties are extreme — almost too 

 " much to be considered varieties, unless proved to be so by actual 

 " breeding from the Qgg" 



The only correct method by which to arrive at a conclusion as to the 

 species constituting the genus Colias, would be the tracing of the imago 

 (true form or variety) to the plants on which it deposits its eggs. It is 

 possible that eggs deposited by a single female on two distinct American 

 plants may produce larvae showing variation from each other and from the 

 ordinary coloration of larvae of the original type, which may have been 

 described in another latitude, and taken on a third food plant. These 

 variations are known to occur, and a wide difference is seen between 

 many species which systematists term representative American forms of 

 European types. There is no question that great deviation exists between 

 the species which are found on the two Continents, and the cause of such 

 variation is what is now wished to be arrived at. We find certain 

 butterflies localized or kept within a certain range, because climate 

 restricts the growth of the bulk of that class of plants on which they 

 feed. In such a case, one hundred examples of the butterfly will probably 

 show no more variation than is general between the sexes, and I give- 

 Pieris ( Gajioris) borealis as an illustration of this fact. Larvae of the 

 greater portion of North American Diurnals are said to feed on from two 

 to ten distinct plants, and I am of opinion that it will yet be proved, when 

 proper attention is given to Entomology in connection with Chemical 

 Botany, that many of the perplexing varieties occurring among the true 

 forms are produced by the food '■' which sustain the larvae. 



* Note. — W. S. Coleman, in his remarks on the brilliant metallic spots which 

 adorn the chrysalides of Inittei flies, says: "This golden effect is produced by a 

 " brilliant white membrane underlying the transparent yellow outer skin of the 

 " chrysalis (Cyntli'ta ccrduij, and it may be imitated, as discovered by Lister many 

 " years ago, by putting a small piece of black gall in a strong decoction of nettles ; 

 "this produces a scum which, when left on caji-paper, will exquisitely gild it, without 

 *' the application of the real metal." 



Late experiments made by a French Entomologist on caterpillars of a Bombyx^ 



