INTRODUCTION. xiii 



the microscope, that lie is lost at the start unless he has a book 

 to help him, which this one hopes to do. But is it necessary 

 to say that the following pages do not contain notices of ev- 

 erything to be found in the ponds and ditches? The begin- 

 ner will capture many objects which he will not find described 

 here. It is not possible that the matter should be otherwise. 

 The waters are crowded with life, and it is only the common- 

 est objects and those most frequently found, that a little book 

 of this kind can attempt to include. 



The descriptions of those few have been made as plain as 

 possible. The writer has seldom allowed himself to "fall into 

 poetry," although often sorely tempted. The keys or analyti- 

 cal tables so freely scattered through the pages have been pur- 

 posely made as artificial as they could be. They use the most 

 conspicuous external characters without regard to scientific 

 classification, and without regard to any result but one only- 

 to help the beginner find the name, at least the generic name, 

 of his specimen. If this is accomplished the book will have 

 attained its purpose. The method of using the keys is ex- 

 plained on page 70. 



Finally, to the beginners in the use of the microscope, for 

 whom the book has been prepared, the writer would say, as 

 has so often been already said : There is DO royal road. The 

 mother-bird finds and brings the food, but even the youngest 

 nestling opens its own mouth. 



