INTRODUCTION. x i 



would know how to seek aid from these celebrated men? And 

 if the student is alone in a country place where Nature smiles 

 her sweetest, but where there are no libraries and no human 

 being to consult, except, perhaps, " the minister," how then shall 

 he learn the name of the flower, the stone, or the bird that at- 

 tracts his attention? "The minister" is usually poor authori- 

 ty on such subjects, and the boy, after wondering and investi- 

 gating in an awkward and boyish fashion, soon gives it up, 

 when he might have become a lover of nature, and perhaps a 

 lover of something even better than nature. The " Agassiz 

 Association," with its clubs and chapters and auxiliary natural 

 history societies, is doing much good in awakening a desire in 

 its young members to know something of natural science, and 

 in doing something to help the young investigators. Yet it 

 can do but little. The workers must depend upon themselves, 

 and the books, of which there are so few adapted to their needs. 



The microscope is every day becoming a more familiar in- 

 strument to the young. There is a growing interest among 

 the boys and girls, even among those of a larger growth, in the 

 little things of the world, and the number of so-called micro- 

 scopists is rapidly increasing. But the possessor of an instru- 

 ment looks at the two or three mounted objects supplied by 

 the dealer, and then wonders if this is all, and if this is the 

 only foundation for the charming stones he has heard of the 

 charming things to be seen with the microscope. 



" Will you tell me where I can find a book that will help me to 

 know a microscopic plant from a microscopic animal, and teach 

 me how I can best collect them?" is a question that has often, in 

 some shape, been asked the writer, and has as often remained 

 unanswered, for there is no book on common American micro- 

 scopic objects. It is only possible to direct the questioner to 

 the ditches and the ponds, and to wish him a success that is 

 almost hopeless. In any event, the beginner naturally, and al- 



