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 Nature, and in its appendixes, Linne has described 

 2840 species oflnsecta and Arachnida, 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 Phanceus c were 

 followed, it would not call for more than 2000 could 



* Mr. MacLeay says that more than 100,000 Annulosa exist in 

 collections. Hor. Ent. 469. 



b Vigors in Zoolog. Journ. I. ii. 188. c Hor. Entomolog. 125. 



