vi A LABORATORY MANUAL OF BOTANY 
should be stated by the teacher or in the text in a clear and 
definite way, leaving the student to work out things that 
are within the range of his maturity, and that will accrue 
most to his interest and profit. 
This manual has been prepared in harmony with these 
convictions. In all his directions the author has aimed to 
make the study of botany full of meaning, of pleasure, and 
of profit to the young people who are to study the subject; 
to lead them to observe constantly and accurately; to form 
well-founded judgments from their observations; to inspire 
them with an intelligent and abiding love for nature; and 
to have them see and appreciate the ways in which the lives 
of plants are allied to their own lives. 
The manual is divided into two parts: Part I considers 
plants from the view-point of their physiology and ecology, 
while Part II considers their structure and evolution as 
they have developed with reference to the problems of nutri- 
tion and reproduction. Hither part may be used as the 
basis of a course in botany. When both parts are used, 
covering a year’s course, the second may precede the first, 
if this order seems preferable. In either case Chapter I is 
essential as an introduction. 
The lessons are outlined for a laboratory period of from 
ninety to a hundred minutes, though in some cases the work 
can not be completed in that time. In schools where a 
laboratory period is not more than thirty or forty minutes 
it will be necessary to shorten the lessons or to use two 
periods to each outline. In most cases each outline may be 
divided easily into two or more lessons as needed. Assign- 
ments from the text used should accompany the laboratory 
lessons as closely as possible. 
The questions at the close of the lessons are not intend- 
ed to be exhaustive, and thoughts and inquiries along simi- 
lar lines will occur to both teacher and pupils. 
The materials for study suggested at the beginning of 
