144 THE CANADIAN ENTOMOLOGIST. 



Museum of Natural History, where many and even little varying species 

 are to be seen in long series, sometimes from one locality. Some may 

 think that such is a waste of space, but there is this to be said in its 

 favour, that whereas a long and picked series of one species, from one 

 locality or many, may indicate to what extent it varies, a long series of 

 another may indicate that that varies but little at all. 



It has been admitted by many men of science that, at any rate, a very 

 large number of so-called "genera" are purely conventional terms, for the 

 mere convenience of the student. As an instance, let me go back twenty- 

 one years and quote Prof. Smith's words in Bulletin No. 38,'*' U. S. N. M., 

 page 6 : "I had at one time the strong conviction that genera were 

 natural assemblages, capable of strict limitation, and definite in extent. 

 The study of a very large material since that time has convinced me that 

 my first impression was erroneous, that genera as such are mere artificial 

 divisions of convenience, useful for the purpose of identification, and for 

 the expression of relationship, and that they were useful for that purpose 

 just in proportion as they expressed clear and definite association of 



characters The limits to which generic division may be 



carried will depend entirely upon the tact and individual propensities of 

 an author, and in a large part also upon the tendency of the time at which 

 he is writing. After a period of wild generic creation, there comes usually 

 a reaction, in which lumping is carried to an extreme, and this is true as 

 to species as well as genera." Yes, and through it all the species remain 

 the same. Like Br'er Rabbit, they " lie low and keep on sayin' nuffin' !" 

 Yet generic division is apt to be looked upon as the acme of science, to 

 say nothing of the designation of certain forms as " new species," without 

 the least idea of the extent of their variation, or the character or sum of 

 characters which, through their sundry phases of variation, may present 

 evidence that they are alien from their allies, or at any rate from forms 

 from which they are assumed to differ biologically. Too much is taken 

 for granted. Too much is stated as fact that is really pure speculation, 

 without evidence being brought forward in support of the hypothesis. It 

 seems to me that he is just as true a student of nature who is constantly 

 testing those facts and bringing all available evidence to bear upon them, 

 not from one point of view alone, but from all the various sources from 

 which it may be drawn. 



*Revision of Agrotis. 



