110 THE CANADIAN ENTOMOLOGIST. 



■most of the Pamphilas, and these last are usually smooth, but some, like 

 P. Napa, are indented like a thimble. Of this shape also are the eggs of 

 Megathymus and Pyrrhopyga ^rax^j-y others are melon-shaped and ribbed, 

 as Nisoniades and Eudamus, and the egg of Farnphila. Zadu/on (an abund- 

 ant species of its genus), is of this type. Pholisora Catullus has a 

 thimble-shaped egg, ribbed vertically and crossed horizontally by Unes, 

 while the top is curiously indented in rounded ridges. It looks much 

 like a confectioner's jelly-mould. 



Dr. Weismann, Descendence-Theory, English edition, shows that the 

 larvae of butterflies in nearly all genera have a morphological congruence 

 with the imagines. " The morphological congruence between larvae and 

 imagines declares itself most sharply in genera, where it is the rule almost 

 without exception. In this case, we can indeed be sure that a genus or 

 sub-genus founded on the imagines, will, in accordance with correct 

 principles, present a corresponding difference in the larvae," p. 444. This 

 is just as true of the egg stage of the American species, with fully 150 of 

 which I am acquainted. Therefore this congruence makes the study of 

 the preparatory stages important. Until recent years, very little at- 

 tention has been paid to this matter, and Dr. Weismann is the first author 

 so far as I am aware, who has treated the larval and pupal stages philo- 

 sophically. Whenever eggs are obtained they should be described from 

 the fresh e'xample, the form and markings noted down, and whenever 

 possible they should be examined under a powerful microscope. By all 

 means, if it is practicable, a drawing should be made on a greatly enlarged 

 scale. Two or three of each species should be preserved in alcohol or 

 glycerine for future reference. Probably glycerine is best, as eggs taken 

 out of alcohol are apt to collapse when dry, and ribbed eggs, like those 

 of Colias, sometimes change in shape in alcohol, expanding in diameter, 

 with flattening of the ribs. Small glass tubes are better than narrow- 

 necked vials for keeping examples of eggs or young larvae. From these 

 last it is rather difficult to remove objects. 



Most eggs are green when laid, yellowish, as in Pieris, Colias, and 

 many Papilios, bluish, as in Grapta, grayish, as in Limenitis. Lycaena 

 has a deep green surface concealed by a white net work, but which can be 

 peeled off. Parnassius is white, Pholisora Catullus is brown ; the Hes- 

 perian eggs as a rule are white. Many eggs turn red a few hours after 

 deposition, as Colias, Anthocharis. Mel. Fhaeto?i turns lake-red. And 

 all these, as well as most other species, change to black before hatching, 



