114 Mr. H. T. Stainton on Genera. 



genera for every slight discrepancy of structure, it is evident 

 that we liave a certain carte blanche allowed us, and there is an 

 elasticity, so to speak, about genera. 



Supposing again in our genus of twenty species there are found 

 some half dozen that agree amongst themselves in the develop- 

 ment of some particular organ, and have so strong a family like- 

 ness that they are at once recognised as forming a group ; here 

 we might, without causing a difficulty, create these species into a 

 genus ; — but whether that genus would eventually stand is a point 

 which would remain for future solution when new species occurred. 

 If such new species were found agreeing rigorously with the 

 characters on which the new genus was constituted, such species 

 would tend to confirm the stability of the genus ; but supposing, 

 on the other hand, any new species that might be met with formed 

 connecting links between the new genus that had been erected, 

 and the remaining species of the old genus from which it had 

 been separated, the new discoveries might in this way completely 

 bridge over the chasm between the two genera and again reunite 

 them into one. 



Though it is an evil to have many genera consisting only of 

 single species, this cannot always, in the gradual progress of 

 science, be avoided. Sometimes species are met with so peculiar 

 in some one or more of their organs that they cannot be referred 

 to any known genera, though it will sometimes happen that the 

 discovery of further species may eventually show that such insects 

 are only the extreme and abnormal forms of existing genera. 



Hence it will be found, that, as we progress in the discovery of 

 species, some new genera will be created, and some genera will be 

 merged into others, perhaps again after a lime to be revived as 

 distinct. A more rigorous examination of structure, and a closer 

 acquaintance with the habit of species, will often lead to the 

 formation of new genera, irrespective of the discovery of new 

 species. 



The superficial observer will be apt to complain of this increase 

 in the number of genera as an unnecessary complication of affairs 

 — whereas, in point of fact, it is in reality a step towards their 

 simplification. For if several species agree inter se in the posses- 

 sion of several characteristics, it is simpler to have them as a 

 distinct genus than as a group, somewhat isolated, in a larger 

 genus. 



The fact of our having a series of genera, each consisting of 

 only a single species, does not necessarily imply something de- 

 fective in our notions of genera, because it may happen that each 



