tail CAilADIAN ENTOMOLOGIST. 25 1 



SUBDIVISION OF GENERA. 



BY G. H, FRENCH, CARBONDALE, ILL. 



I was pleased to see Mr. Cockerell's article on this subject in the 

 September number of the Canadian Entomologist, and hope we may 

 hear from others on the question. It seems to me that a genus should, as 

 far as possible, represent a natural division of a group of plants or animals 

 so distinct from other groups that the species forming the genus are easily 

 referred to it. In botany we recognize at a glance such natural genera as 

 Carex, Rosa, Querctis, etc. The fact that the first of these is a large 

 genus is, it seems to me, no good reason why any subdivisions of it should 

 be called genera, for each plant in any one of the divisions is as much a 

 Carex as any other one. If the genus is too large to suit the convenience 

 of the practical worker in some part of his work, I have no objection to a 

 subdivision of the genus into groups ; in fact every botanist knows that 

 the species do readily divide into such groups. Perhaps it is best to give 

 names to these group divisions instead of numbers or letters as is some- 

 times done. The main objection I can see to this is that some one, in label- 

 ling the specimens in his cabinet and in making his exchanges, will use these 

 names as generic, leading to more or less confusion. 



But what is the custom among systematists in different groups of 

 natural history? To answer this question I turn to a few works that come 

 to my hand, and find the following : — 



In Botany I find that Wood divides Carex into two groups without 

 names ; the genus Aster into four groups with names. Mann's Catalogue 

 makes no division of the genera ; published 1868. Gray in his " Manual," 

 1856, subdivides fifty-four genera, using names for the subdivisions, five of 

 these being in the Mosses and Liverworts. In his " School and Field 

 Book " he does substantially the same thing. In his " Synoptical Flora 

 of North America," 1886, he pursues the same plan, the names in most, 

 if not all cases, such as had been used for such subdivisions by some other 

 writer in caUing them genera. 



In Ornithology I find that Coues in " Key to North American Birds," 

 1872, makes no divisions of the genera. Baird, Brewer and Ridgway, in 

 "History of N. A. Land Birds," 1874, divide eleven genera by using 

 subgenera names, and divide one genus by sections that are numbered. 

 Mr. Ridgway does the same thing in "Birds of lUinois," 1885. 



