Proceedings of Scientific Societies

1889 American Naturalist  
x889.] Proceedings of Scientific Societies. 457 8. Although habits and the conditions that surround'the larva~ have been very important features'in the production of the present larval forms, some other force has been at work in producing, or rather in retaining them. For we find a -great variety of larva~ at the present time with almost identical habits. This other force is undoubtedly heredity, which has frequently proved stronger than the modifying effect of the environment. 9. Beetle larva~
more » ... cannot be classified by the same character--istics used in classifying adults. The shape of the antenna~ has no significance in the classification of larvae, since it is almost uniform throughout the order. The shape of the legs, -the number of tarsi, the shape of the coxal cavities, are of not much more value. The mouth parts seem to be of a little 'more value, and are of far less value in classification than they are in the adults. IO. The mouth parts of beetle larve, even in the typical Campodeoid form, are not Campodeoid in type, but approxi---mate rather closely to those of the adult beetles. No-traceable similarity can be found between the mouth parts of any particular family of larva~ and those of the adults of the same family, beyond the general similarity sometimes produced by Alike habits. It is true, however, that the mouth parts of all beetle larva~ are more like those of adult beetles than they are like those of any other order of insects. This is probably an example of what Hyatt and Cope call concentration of de-,velopment, and which is elsewhere called precocious inheritance. It is an instance where the characters of the adult -have been impressed on the larval stages. I I. In beetle larva~ we have quite a number of cases in which a similar larval type has been acquired independently -in two or more families. The above conclusions apply only to the group of Coleoptera, and while some of them will doubtless be found equally -true of other orders of insects, some of them are probably pe--culiar to beetles.
doi:10.1086/274943 fatcat:ox6pgujgbze6lcvxxiz7cwmara