404 SYSTEM OF INSECTS. 
genera : but upon these last it will not be a waste of your 
time to enlarge a little. In the last edition of the Sy- 
stema Naturcc, and in its appendixes, Linne has described 
2840 species o?I?isecta and Arachiiida, which he divided 
into 83 genera, allowing upon an average nearly 35 
species to each genus. From the paucity of the mate- 
rials, therefore, of which his system was constructed, 
there was no loud call upon him for numerous genera. 
But now more than thirty times that number are said to 
have found a place in the cabinets of collectors a , and 
there is good reason for thinking that perhaps half that 
are in existence are as yet undiscovered ; — this makes 
it a matter of absolute necessity to subdivide the Linnean 
genera, which in fact, with regard to the majority of 
them, were the 'primary groups of his Orders, rather 
than an approximation to the ultimate. But this prin- 
ciple may be carried too far : for it is the nature of man 
to pass from one extreme to the other : and this seems to 
me to be the case when it is proposed to make genera the 
extreme term of subdivision before you arrive at species. 
But it is argued by a very acute Zoologist, that simplicity, 
perspicuity, and room for necessary variations are best 
preserved by distinguishing these subdivisions each by 
an appropriate name b : — Granted. But still it is only a 
choice of evils. It would require probably more than 
10,000 names to designate them, were every extreme 
group distinguished by a name : but if Mr. MacLeay's 
admirable pattern exhibited in his genus Phanaas c were 
followed, it would not call for more than 2000 — could 
* Mr. MacLeay says that more than 100,000 Annulosa exist in 
collections. — Hoi: Ent. 469. 
" Vigors in Zoolog. Journ. I, ii. 188. c Hor. Entomolog. 125 — . 
