THE GENUS CAMPODEA. 45 



strength or from any change of season, alters, how- 

 ever shghtly, its habits or food, immediately it be- 

 comes subject to the action of distinct forces ; natural 

 selection affects it in two different, and it may be very 

 distinct, manners, gradually leading to differences 

 which may become so great as to involve an inter- 

 mediate period of change and quiescence. 



M. Brauer^ believes that among existing types, 

 the genus Camjyodea most nearly represents the 

 original insect stock, and, like MiiUer, he considers that 

 there were perfect insects before there were larvse or 

 pupffi. 



He quotes the cases of Meloe and Sitaris as proofs 

 that the sluggish, grub- or caterpillar-type of larva 

 is to be regarded, not as a developmental form, but 

 as an adaptational modification of the earlier, active 

 hexapod form. As is well known, the larvae of the 

 beetles belonging to these genera quit the egg as 

 active, hexapod little creatures, and subsequently turn 

 into fat, sluggish larvae, living in the cells of bees, 

 and feeding on the honey intended by the bee for her 

 own young." These cases, however, must, I think, be 

 ranked rather among the number of those in which 

 the development is, to use M. Brauer's own expres- 

 sion, " falsified by the struggle for existence " (gefalscht 

 durch den Kampf urn's Dasein), and which, therefore, 

 do not truly indicate the successive stages of evolu- 

 tion. 



Mr. Darwin,^ in the fourth edition of the ' Origin of 

 Species,' has also some interesting remarks on the 

 same subject : 



" Fritz Midler, who has recently discussed this 

 whole subject with much ability, goes so far as to 

 believe that the progenitor of all insects probably 

 resembled an adult insect, and that the caterpillar or 



^ " Betraclitungen iiber die Verwandlung der lusecten." ' Wien. Zool. 

 Bot. Gesell.,' 1869. 



2 ' Newport Linn. Trans.,' 1851. Fabre, ' Ann. des Sci. Nat.,' ser. 4, 

 vol. vii. See also ' Natural History Review,' 1863, p. 121. 



^ ' Origin of Species,' 4tli edit., p. 530. 



