INTRODUCTORY REMARKS. IX 



The beginner in scientific studies is apt to be 

 discouraged by the boundlessness of the field over 

 which he glances. The number of the objects of his 

 study is so vast, that he knows not where to begin 

 his selection. And, indeed, this view is sometimes 

 depressing to the experienced naturalist, who loving 

 his science for its own sake, earnestly desires its per- 

 fection ; but who is compelled to feel how little pro- 

 gress can be made in the short period of his life. 

 In Entomology, not much less than a hundred thou- 

 sand species are already named, without a limit being 

 even approached.* But in another view, the very 

 vastness of the subject is an encouragement to per- 

 severance, as patient observation is sure to be re- 

 warded by the discovery of new facts. And here we 

 may notice an erroneous opinion, which is liable to be 

 entertained in the outset of an attempt at out-of-door 

 observation ; that the familiar animals around us are 

 already so well known, as to afford no probability of 



* The present state of science affords data for Zoologists to conjecture, 

 with some approximation to truth, the probable number of existing species 

 of animals. Mr. Swainson has given the following as his estimate, 

 deduced from facts and principles already known. (See Geog. and Class, 

 of Quadrupeds, page 28.) 



Quadrupeds . . . 1200 Worms . . . 2500 



Birds 6800 Radiata . . . 1000 



Reptiles .... 1500 Polypes, &c., . . 1500 



Fishes 8000 Testacea . . .4500 



Insects .... 550,000 Naked Testacea . . 600 



making a total of 577,600 species. We may be permitted to observe 

 that to us, this estimate appears, in several particulars, to be much within 

 the probable limits. 



a 5 



