10 THE BUTTERFLY VIVARIUM. 



Nyssia zonaria, as I recollect, made a great im- 

 pression upon me at the time — being then a very 

 young entomologist — for they were Geometridce, that 

 is, what are popularly termed Loopers, from the 

 curious manner in which the body is alternately 

 looped and extended in their peculiar method of 

 locomotion. In these evolutions the long graceful 

 forms of the slender bodies of these caterpillars, 

 which are of a deep green, with a single longitudinal 

 line of brilliant yellow, were seen to the greatest 

 advantage ; and I did not rest till I, too, had a 

 brood of Nyssia zonaria. 



But though insects may sometimes be reared 

 successfully by such simple means as those de- 

 scribed, it can only be done by very constant atten- 

 tion, and with the experience of a thoroughly 

 practised field entomologist, well acquainted with 

 all the requirements of the insects. One of my 

 own first experiments upon a similar scale, for 

 instance, was very signally and fatally unsuccessful. 

 I had discovered a brood of the remarkable, 

 though common, larva? of Vanessa Io, feeding on 

 a bed of nettles; and observing their singular 

 branching spines, several of which issue from each 

 segment of the body, I imagined them to be 

 creatures as rare as they were curious, and carried 



