VI PREFACE 



have been taught by the " verification method " have 

 confessed committing to memory the detailed descrip- 

 tions of their specimens in preference to doing the 

 work necessitated by a practical examination. It is 

 needless to say that with such students laboratory 

 work fails completely to accomplish its fourfold ob- 

 ject — viz., to teach the student, first, to observe cor- 

 rectly; second, to distinguish essential from non-essen- 

 tial facts ; third, to draw proper conclusions from the 

 facts observed ; and fourth, to express in writing and 

 by means of drawings the results obtained. 



For the purpose of developing in the student the 

 power of independent observation, to teach him that 

 the source of all knowledge is not " the book " rather 

 than the specimen, that there is a great deal to be seen 

 besides that which "the book" describes, and that he 

 is not to consider that, though his observations may 

 not agree with those of "the book," the latter must, 

 necessarily, be right — ^ these are the reasons why this 

 guide has been written. 



The guide consists essentially of questions on the 

 gross and minute structure and on the physiology of a 

 series of common animals and plants which are typical 

 of their kind — questions which can be answered only 

 by actual examination of the specimen or by perform- 

 ance of the experiment. Directions are given for the 

 collection of specimens, for their preservation, and for 

 preparing them for examination, also for performing 

 simple physiological experiments. Particular species 

 are not required, as the questions usually apply equally 

 well to several related forms. 



