The Colours of Animals. 79 



dissimilar larvae. Indeed, a classification of insects 

 founded on larvae would be quite different from 

 that founded on the perfect insects. The group to 

 which the bees, wasps, and ants belong, for instance, 

 and which, so far as the perfect insects are con- 

 cerned, form a very natural division, would be 

 divided into two ; or rather one portion of them 

 namely, the saw-flies would be united to the but- 

 terflies and moths. Now, why do the larvae of 

 saw-flies differ from those of their allies, and re- 

 semble those of butterflies and moths ? It is 

 because their habits differ from those of ants and 

 bees, and they feed on leaves like ordinary cater- 

 pillars. 



9. In some cases the form changes considerably 

 during the larval state. From this point of view, 

 the transformations of a small beetle, called Sitaris, 

 which have been carefully observed by M. Fabre, 

 are peculiarly interesting. 



10. The genus Sitaris, which is allied to the 

 blister-fly and to the oil-beetle, is parasitic on a 

 kind of solitary bee which excavates subterranean 

 galleries, each leading to a cell. The eggs of the 

 beetle, which are deposited at the entrance of the 

 galleries made by the bees, are hatched at the end 

 of September or beginning of October, and we 

 might not unnaturally expect that the young larvae, 

 which are active little creatures with six serviceable 

 legs, would at once eat their way into the cells of 

 the bee. No such thing : till the month of April 



