OF THE ANNULOSA. 365 



nim^ conitiventibus, sed margine interiori impositis." If to 

 this it be added that both groups undergo the same sort 

 of metamorphosis, we shall have little occasion for conjec- 

 ture to obtain the reason of M. Latreille's having followed 

 the example of Linnaeus, and continued to place them to- 

 gether in the Regne Animal. At first sight there is cer- 

 tainly sufficient to warrant the supposition of an affinity 

 existing between them ; but a more careful examination 

 assures us that there is httle similarity either in their or- 

 gans of manducation or in their internal structure ; and 

 above all, that, on placing them together, we interrupt 

 that very evident series of affinities which is composed of 

 insects living by suction. This relation, therefore, which 

 exists manifestly between a Cimex and a Grylhis is one 

 of analogy, and not of affinity. 



Secondly, In the same way many Dipterous genera, as 

 Musca, Sicus, Vohicella, Loxocera, &c., imitate Hymeno- 

 ptera in certain respects, either of economy or appearance, 

 so accurately as not unfi-equently to deceive even scientific 

 observers ; and a non-descript and unique hymenopterous 

 insect in my father's possession, is on the other hand well 

 known as having completely adopted the disguise of some 

 Dipterous genus without losing any one of the essential cha- 

 racters of Hymenoptera . Thirdly, There is also an evident, 

 though perhaps not so close, analogy between Homopte- 

 rous insects (as Tettigonia) and some Neuroptera. This did 

 not escape the penetration of M. Latreille ; but, as usual 

 from confounding it with a relation of affinity, he has placed 

 together two groups totally distinct, and by that means 

 broken a very regular transition of affinities. Fourthly, 

 Lyonnet, the most indefatigable of naturalists, made like- 

 wise no distinction between analogy and affinity, when, in 



