PREFACE. Xi 



To elucidate the whole, he has annexed a set of 

 explanatory plates, etched by himself, from sketches 

 of his own ; rudely executed indeed, but he hopes 

 sufficiently accurate to illustrate his system. 



After all, the author is conscious that he brings 

 far from a perfect work before the tribunal of the 

 public. Much still remains incomplete; and many 

 errors, no doubt, will require future correction. 

 An account of any genus, perfect and elaborate in 

 all its parts, must be the work of him who is versed 

 in the history and economy of every individual that 

 belongs to it. He, and he only can go upon sure 

 grounds, for no other person can in all cases, with 

 certainty, distinguish the species from the variety, 

 and unite each sex to its legitimate partner. But 

 so much knowledge, even with respect to a single 

 genus, where the species are numerous, is not to 

 be expected from one man : nor should the natu- 

 ralist attempt, like the spider, to weave his w^eb from 

 materials derived solely from within himself; but 

 rather let him copy the industrious bee, and draw 

 genuine treasures from those flowers of science 

 which have been reared by other hands, and com- 

 bining these with his own discoveries, let him en- 

 deavour to concentrate all into one harmonious 

 system, with parts curiously formed, arranged, and 

 adapted to each other, and to the whole; and cal- 

 culated to preserve the sweets of true wisdom pure 

 and unsophisticated. 



a 4 The 



