172 



alls, the eggs are not shaped : only fatty masses are found in the 

 ovaries. It is just as in Argynnis cyhele, on its first appearance 

 in August, and in that sj^ecies the eggs mature and are ready 

 to be laid in about 15 days after the first butterflies are seen. 

 This I have ascertained by many dissections and observations, 

 in course of several years. 



The eggs of D. archippus are laid singly on the leaves of 

 its food-plant, and by preference on young plants. In the lat- 

 ter part of suimner these spring up in abundance about my 

 grounds, after the grass and weeds have received their annual 

 cutting, and I can at any time be sure of finding eggs. In al- 

 most all cases they are laid on the upper side of the leaf, and 

 sometimes there are two or three on the same leaf. But these 

 have usually proceeded from different females, or have been 

 laid at different periods, as may be known by the freshness 

 of some and the maturity of others. At the same time larvae 

 of any stage may perhaps be feeding on the same plant. The 

 young larva eats its egg-shell and presently attacks the fleshy 

 surface of the leaf, eating out a narrow ring, of about 6 mm. 

 diameter. After the first moult it is strong enough to cut 

 the leaf through, and henceforth feeds on the edges. 



There has been some diversity of statement as to the num- 

 ber of moults of D. archippus, but there are four, as I have 

 already said. In all my experience with larvae of butterflies, I 

 know of only one species which has but three moults, viz., JVeo- 

 nympha gemma Hiib., and I should not assert this if I had not 

 verified it repeatedly. JV. sosyhius, N. areolalus and N. eury- 

 tris, placed in the same genus, all have four moults. Indeed 

 nearly all butterflies have four, but a few of them five. P. 

 philenor has five, while all the other Papilios found in the 

 northern states have but four. The hibernating Argynnids 

 have five, as do the Phyciodes, but those which are many- 

 brooded pass but four moults in the summer. Nearly all my 

 rearing of larvae is done in quarter litre ^ jaWj glasses, with tin 

 tops. In these the plant keeps fresh a long time, and I have not 

 found that the larvce suffer from the close confinement. The 

 tops are lifted two or three times a day at least, and the 



1 i. e., half pint. 



