1823.] On Mr, MacUay^s Doctrine of Affinity and Analogy, 417 



Article V. 



A Description of some Insects which appear to exemplify Mr. 

 William S. Macleay^s Doctrine of Affinity and Analogy, By 

 the Rev. William Kirby, MA. FKS.'and LS.^ 



No objects are more interesting to the scientific naturahst 

 than those which assume the external appearance of one tribe, 

 while their more essential characters and their habits indicate 

 that they belong to another. These objects a prima facie sur- 

 vey would often induce us to refer to a very different set of 

 beings from that to which a more intimate acquaintance with 

 their pecuhar diagnostics and economy would lead us. And 

 we shall find, the further we extend our researches, the traces 

 of that plan of Creative Wisdom by which a symbolical relation- 

 shipy if I may so call it, connects such of his creatures, as in 

 other respects are placed in opposition to each other, as well as 

 a natural affinity those that really approximate. Writers in 

 every department of natural history, when they have been 

 endeavouring to thread the labyrinth of affinities, have been 

 extremely puzzled by this remarkable circumstance. They were 

 aware that those species which connect two proximate tribes, 

 generally partake of the characters of both ; but they were not 

 sufficiently aware of this resemblance between objects that are 

 connected by little or no affinity. Hence it has happened not 

 unfrequently, that objects have been referred not to the tribe to 

 which they are really related, but to that which they resemble in 

 some of their less essential characters. 



Mr. W. S. Macleay, in his acute and learned Hora Entomo- 

 logicce, has furnished the naturahst with a clue which, if heed- 

 fully followed, will enable him to guide himself through all the 

 intricacies with which the circumstance here mentioned has 

 perplexed his path. This gentleman has first stated with clear- 

 ness and precision the distinctions, so often before confounded, 

 between real affinity and those resemblances which are merely 

 analogical ; and has proved satisfactorily, that there exist 

 between numerous objects in every department of nature striking 

 coincidences as to external characters, which do not indicate 

 that they are related to each other, or should be placed together 

 in a natural arrangement. 



In confirmation of the doctrine here alluded to, I have the 

 honour to present to the Linnean Society a description of three 

 new genera of insects which appear to wear the face of a tribe 

 to which they do not belong. 



* From the Linnean Transactions hr 1823, Part I. 



New Series, vol. vi. 2 e 



