14 Introduction 



of larvEe, campodeaform or blattoid; if, indeed, there is any phylo- 

 genetic significance in such forms. There are, moreover, a number 

 of larval forms that are apparently very pecuUar, as in Dermestidse 

 and Coccinellidse ; and many of the Polyphagous larvae exhibit modi- 

 fications in various directions. 



In the decidedly derivative series the larvae apparently show uni- 

 form progressive modification in a definite direction. The larvae of 

 LamelUcornia are eruciform, fat, curled grubs, thickened at anal extrem- 

 ity, but still with legs. The larvae of the Phytophaga are also eruciform, 

 sometimes mth, sometimes without, legs; in Bruchidse the young larva; 

 have legs that are lost in the later moults. The larvae of the Rhj-Ticho- 

 phora (except Brentidae) are always curled, legless grubs. There seems 

 thus to be a progressive development from the active larvae of the Ade- 

 phaga, through the PolyiDhagous and Lamellicorn forms of larvae, that 

 reaches its climax in the slothful seed-eating larvae of Rhynchophora. 

 Packard has traced an interesting parallel between this development 

 and the life history of hypermetamorphic beetles as stated by Riley ' 

 and others. If one compares Riley's figure of the first larva (or triun- 

 gulin) with the campodeaform larva of Adephaga, and his figure of the 

 last larval stage with the eruciform larva of Rhynchophora, a striking 

 resemblance will certainly be detected. The history of the development 

 of Coleopterous larv^se seems to be repeated in the various moults. 



But when one considers the legless larvae of the Buprestidae and 

 Eucnemidae, groups that retam many characteristics we have called 

 primitive, the active larvae of many Coccinellidae, a group that in many 

 respects seems highly derivative, one is forced to consider the gradual 

 loss of larval legs as possibly the result of atrophy, rather than as an 

 indication of phylogenetic rank. The references made by Handlirsch 

 to the blattoid form of larva as characteristically primitive are still more 

 disconcerting, for such forms are rare in the Adephaga (Cychrus is an 

 example and it is certainly far from the most primitive of Adephaga) 

 though his fossil evidence strongly favors their early origin. 



It seems too early in the study of Coleopterous larvae to attempt to 

 ch'aw any definite conclusions therefrom, except as a corroboration of 

 those drawn from the study of adults. Mr. Schwarz has given long 

 study to the subject; and his present feeling, as I gathered from a 

 recent conversation with him, is not very different from that I have just 

 expressed. Dr. Boving's results and those of Dr. F. C. Craighead, 



' On the Larval Characters, etc. (Trans. Ac. Sci. St. Louis, III, 1877, pp. 544-562). 



