88 THE BUTTERFLY VIVARIUM. 



of the Stag Beetle, does not change for six years ; 

 while some of the wood-eating larvae are supposed 

 to live in that stage very much longer. 



In the " Linnaaan Transactions," for instance, 

 there is an interesting account hy Mr. Marsham of 

 the coming forth of the perfect form of Buprestis 

 Splendens, an exotic insect, which is a wood-borer 

 in its larva stage, and which he infers, from the 

 following circumstances, must have passed full 

 twenty years in the larva state : — In the year 1810, 

 the perfect insect emerged from the wood of a desk 

 made of foreign wood, for a public office, in 1788-9, 

 from which the long period of its larva existence 

 seems pretty clearly shown. It would seem that 

 meat-eating larvae undergo their change most 

 quickly, and that those feeding under ground, or 

 in wood, are the most tardy in their transfor- 

 mation; while those which are leaf-feeders, such 

 as those of Butterflies, etc., bold a medium place. 



Among water larva) it may be noticed that tbose 

 of Gnats change in a few weeks; those of the 

 Dragon-fly tribe, according to De Rambur, in about 

 a year; while some of the Ephemera, as though 

 to compensate for the exceeding brevity of their 

 existence in their winged state, live several years in 

 that of an aquatic Grub. The manner in which 



