V1 PREFACE 
most worth which touches the pupil’s daily hfe at the most 
points, and therefore best enables him to understand his own 
environment. On the other hand, the author has no sympathy 
with those who decry the use of apparatus in botany teaching 
in secondary schools and who would confine the work of their 
pupils mainly within the hmits of what can be seen with the 
unaided eye. If the compound microscope plainly reveals 
things shown only imperfectly by a magnifier and not seen at — 
all with the naked eye,— use the microscope! If iodine 
solution or other easily prepared reagents make evident the 
existence of structures or substances not to be detected with- 
out them, — then use the reagents! No one thinks of deny- 
ing a boy the use of a spyglass or a compass for his tramps 
afield or his outings in a boat because he has not studied 
physics. No one would refuse to let an intelligent boy or 
girl use a camera because the would-be photographer had not 
mastered the chemical reactions that follow upon the expo- 
sure of a sensitized plate. Yet it is equally illogical to defer 
some of the most fascinating portions of botanical study until 
the college course, to which most never attain. When the 
‘university professor tells the teacher that he ought not to 
employ the ordinary appliances of elementary biological inves- | 
tigation in the school laboratory because the pupils’ cannot 
intelligently use them, the teacher is forced to reply that the 
professor himself cannot intelligently discuss a subject of 
which he has no personal knowledge. The pupils are deeply 
interested; they prove by their drawings and their recita- 
tions that they have seen a good way into plant structures 
and plant functions; then why not let them study botany 
in earnest ? 
J. Yom 
CAMBRIDGE, January, 1901. 
