LOCALITIES OF VARIOUS SPECIES. 71 



numerous specimens of which we collected in the 

 immediate vicinity; but the flies of these, from their 

 previous exposure to the cold out of doors, did not 

 appear till a month later. It is worthy of remark, 

 that the two exotic plants are of the same natural 

 family (Composites) , yet, notwithstanding the simi- 

 larity of the common groundsel (Senecio vulgaris) to 

 the American, not one leaf of the former was found 

 mined, though it is an abundant native plant.* 



It is no less remarkable, that the mother insects 

 of the larvas which live solitary and those which 

 live in society take care to deposit their eggs with 

 regard to the respective destinations of their pro- 

 geny. In our earlier studies we remember being much 

 interested with Harris's description of the admirable 

 butterfly ( Vanessa Jltalanta)^ flitting rapidly and 

 stealthily from field to field, and depositing only a 

 single egg on a single nettle in each, as if she were 

 afraid of overstocking one place and leaving others 

 uninhabited by her descendants.! Our subsequent 

 observation of the mariners of the insect itself has led 

 us to doubt the accuracy of Harris; for we think it 

 will hold as a pretty general principle, that the mo- 

 thers of solitary caterpillars, for the most part, deposit 

 several eggs on the same plant, often at no great 

 distance, and sometimes on the same leaf. No class 

 of caterpillars could well be considered more solitary 

 than those of the hawk moths (Sphingidce, LEACH), 

 yet we have found from two to three eggs of that 

 of the popular hawk ( Smerinthus Populi) upon the 

 same leaf, and a similar number of the eggs of the 

 puss moth, the larva of which is also solitary, on one 

 leaf ;J while of the admirable butterfly above alluded 

 to, we found, in 1825, as many as from three to six 

 on every plant in a small patch of about a dozen 



* J. R. t See Harris's Aurelian, vi, fol. Lond. 1778. 

 | See Insect Architecture, p. 192. 



