PEEFACE 



from the examination of living organisms is lost be- 

 cause few people know how and what to observe. To 

 most individuals the study of Natural History means 

 nothing inore than the memorizing of Latin names, of 

 long descriptions consisting of unfamiliar terms, of 

 " collecting " various kinds of disagreeable creatures, 

 and preserving them dried or in alcohol, etc., etc. 



Should this guide, even in the slightest degree, prove 

 instrumental in doing away with such a belief and in 

 cultivating a taste for the study of nature, then Avill it 

 have accomplished its purpose. 



In one of the appendices is given, under its appropri- 

 ate heading, a list of literature which the student may 

 profitably consult after having finished the study of 

 each organism. In the construction of the guide free 

 use has been made of the works named. In another 

 appendix is given a brief list of the reagents and some 

 of the appliances needed in carrying out the work 

 given in the body of the manual. For more detailed 

 directions and descriptions the student is referred to 

 the works on microscopical technique and laboratory 

 methods. 



Acknowledgment is due to Mr. Arthur Willey, of 

 Columbia College, who kindly looked over the proof- 

 sheets and made a number of valuable suggestions. 



C. W. D. 



