ABOUT THE INSECTS. 363 



is not divided into those which have, and those which have 

 not, articulated members. 



The first subdivision includes Insects, Arachnida, Crustacea, 

 and Myriapoda the second, Annelida and Entozoa. 



Some naturalists, be it said, rank the Cirrhopoda as inter- 

 mediate between the two; others place them among the 

 Mollusca. Others, again, include the Rotifera in the second 

 sub-division. 



We shall in this place confine our remarks to the Insects. 

 According to the most distinguished entomologists, the average 

 number of species at present, described or not described, and 

 preserved in entomological collections, is between 150,000 and 

 170,000. 



This estimate is obviously below the truth. Take only the 

 Coleoptera, which forms but one, though, it is true, the most 

 numerous order of insects. Thirty years ago the most com- 

 plete collections contained about 7000 species. In 1850, the 

 museum at Berlin, according to Alexander von Humboldt, 

 contained nearly 32,000. We would here call the reader's 

 attention to the just remarks of the author of the " Natural 

 History of the Coleoptera," an entomologist of great authority, 

 whom a long residence in America had peculiarly qualified to 

 pronounce an opinion on the subject before us : 



" If we remember," says the Count de Castelnau, " that 

 tnere are immense regions in Asia and the two Americas of 

 which we do not possess a single coleoptera ; if we reflect that 

 the interior of the vast continent of New Holland is, from this 

 standpoint, entirely unknown, and that most of the archi- 



