VI PREFACE. 



contract of error between the deliverer and the receiver ; for 

 he that delivereth desireth to deliver it in such a form as may 

 be best believed, and not as may be best examined ; and he 

 that receiveth knowledge, desireth rather present satisfaction 

 than expectant inquiry, and so rather not to doubt than not to 

 err : glory maketh the author not to lay bare his weakness, 

 and sloth maketh the disciple not to know his strength." 



I would hope, however, that there are some readers who 

 will feel thankful for my having pointed out to them certain 

 subjects which they, perhaps, may have peculiar facilities 

 for investigating, with pleasure to themselves and benefit to 

 science. Indeed, almost every one possessing the use of his 

 eyes, a habit of careful and scrutinising observation, and 

 a love of truth, has it in his power to contribute to our 

 knowledge of the works and phenomena of creation. He 

 is, indeed, unfortunate who feels that he cannot say with 

 Shakespeare, 



" In Nature's infinite book of secrecy, 

 A little I can read." 



To pursue this study it is not absolutely necessary that 

 a man should be an F. L. S. or an F. R. S., or that he should 

 be able to " nickname God's creatures" in classic languages. 

 All that is requisite is a frequent reference from books to 

 nature, and then again from nature to books; for the latter 

 are certainly essential, although a vast deal has been said 

 in favour of "field naturalists," by those who have published 

 most books for their perusal. 



Although doubtful matters in natural history are often 

 entirely omitted by writers from the apprehension just inti- 

 mated, yet it is more frequently the case that only one view 

 of the question is concealed, the other being arbitrarily ad- 

 duced from no better motive than that it is favourable to some 

 cherished theory, or that it is better adapted to the style of 

 the discourse. What a recent writer has said of political 

 history is too often true of natural history. " Where, as is 



