PEEFAOE Vll 



The material of which the guide is composed has been 

 gradually accumulated during an experience of nearly 

 seven years of teaching high-school and college classes, 

 consisting of students of both sexes and of ages vary- 

 ing from fourteen to fifty years. With the exception 

 of a few additions made while preparing the manual for 

 printing, all of the work herein detailed has been per- 

 formed by college students, and a very large part by 

 students in the second year of their high-school course. 



Although it is thought that the topics are so arranged 

 and the questions so worded that any one of average 

 intelligence can study any or all of the organisms given, 

 still it is not intended that the guide shall supersede 

 the instructor, but, rather, aid him. The student will 

 always require the advice and suggestions of his teach- 

 er, who will need to point out many of the structures 

 which here are only named, and which it would be im- 

 possible to describe so that the student could find them 

 for himself, without defeating the very object which the 

 guide seeks to attain. 



As this manual has to do entirely with the work of 

 the laboratory, it is suggested to those teachers who 

 wish to use a text-book also, that nothing better can be 

 found than Parker's admirable work, "Lessons in Ele- 

 mentary Biology," 2d ed., New York, 1893. 



Following the classification given in the " Text-Book 

 of Zoology" of Olaus and Sedgwick, and the "Outlines 

 of Classification and of Special Morphology of Plants " 

 of Goebel, an attempt has been made to arrange in log- 

 ical sequence the organisms to be studied, proceeding 

 from the simple to the more complicated. It is desira- 



