PREFACE. 



THE following laboratory-directions have been pre- 

 pared for a course in General Biology that extends 

 throughout the collegiate year, and includes work in the 

 laboratory for about six hours each week. 



Experience has shown that there are certain practical 

 advantages in beginning with the fern and the earth- 

 worm, and that the results are not at all inferior to 

 those that follow from, the more logical method of 

 beginning with the simplest organisms. 



The plan of this course is similar to that suggested by 

 the ' ' General Biology " of Sedgwick and Wilson ; and 

 as the directions have been used with large classes for 

 several years, it is believed that they are entirely practi- 

 cable. 



In determining the amount of work to be done upon 

 each form, an endeavor has been made to include the 

 most important points and at the same time to. keep 

 each in its proper relation to the other parts of the 

 course as a whole. But any suggestion of improvements 

 that may occur to any one using the directions would be 

 gladly received by the author. 



The following list of hours has" been found by experi- 

 ence to represent approximately the time needed for the 

 different subjects : 



iii 



297* 



