118 Probable Number of Insect Species, 



animals (nearly synonymous with the Linnaean insects) pre- 

 served in the various collections. 



Messrs. Kirby and Spence, adopting a conjecture of De- 

 candolle, that the number of species of plants may be some- 

 where between 110,000 and 120,000, observe, that, " as a 

 vast number of phanerogamous plants and fungi are inha- 

 bited by several species (of insects), we may form some idea 

 how immense must be the number of existing insects ; and 

 how beggarly does Ray's conjecture of 20,000 species, which 

 in his time was reckoned a magnificent idea, appear in com- 

 parison ! " After instituting a comparison between the num- 

 bers of British insects with that of British phanerogamous 

 plants, whereby it appears that, on the average, there are 

 more than six insects to each plant ; these authors arrive at 

 the conclusion that, " if we reckon the phanerogamous vege- 

 tables of the globe, in round numbers, at 100,000 species, 

 the number of insects would amount to 600,000." If we say 

 400,000, we shall, perhaps, not be very wide of the truth.* 



We will now, however, examine a few of the groups of 

 insects in detail, commencing with the two Linnaean genera 

 of the tiger beetles and predaceous ground beetles (Cicindela 

 and Carabus), which are placed at the head of the Coleoptera 

 by Latreille and his followers. In the Systema Nature, the 

 former of these two genera comprised 14, and the latter 43, 

 species. In the Catalogue of Coleoptera contained in the 

 cabinet of the Baron Dejean, published in 1821, these two 

 genera comprised 908 species; but, since that period, the 

 baron has published the ^description of his own increased 

 collection of these two groups, which occupy not less than 

 six thick octavo volumes : and if we average these volumes 

 to contain 350 species apiece (vol. i. contains 420 ; vol. hi., 

 266), we shall have more than 2000 species, or 40 times as 

 many as were described by Linnaeus seventy years ago. f 



In the rove beetles (Staphylinus), Linnaeus described 26 spe- 

 cies ; whilst Mr. Stephens has enumerated, in his Catalogue, 

 750 British species. % 



In the lamellicorn beetles, composing the genus £carabae v us, 

 Linnaeus described 87 species : Mr. MacLeay, in 1819, stated 

 that his father's collection comprised nearly 1800 species. 



In the weevil genus (Curculio), Linnaeus described 95 spe- 



* I had intended to have introduced some observations upon the advan- 

 tages and disadvantages resulting from the greatly increased extent of our 

 collections ; but I must defer them to another opportunity. 



f Since the above was written I have received the 2d edition of the 

 baron's Catalogue, just published, in which there are 2494 ficindelidae and 

 Carabidae. 



J Dejean, Cat. 2d edit., gives 789 tftaphylinidae from various parts. 



