Observe the leaves of tress shrubs or bushes planted by the roadside Notewhether their leaves
have some dust or soor deposited over them. Take similarobservations with the leaves of trees in
the school compound or in a garden. Is there any difference in deposition of soot on leaves of
trees near the roadside? What could be the possible reasons for this difference?
Answers
A simple and untechnical text to cover this secondary
biology in its elementary phases. The book stands be-
tween the unorganized nature-study of the intermediate
grades and the formal science of the more advanced
courses. It is a difficult space to bridge, partly because
the subjects are so diverse, and partly because some
teachers do not yet understand the importance of im-
parting to beginners a general rather than a special
view point.
Still another difficulty is the lack of uniformity in the
practice of different schools. It is not urged that it is
desirable to have uniformity in all respects, but the lack
of it makes it difficult to prepare a book that shall equally
meet all needs. It is hoped, however, that the present
book is fairly adaptable to a variety of conditions, and
with this thought in mind the following suggestions are
made as to its use :
Being in three separate parts, the teacher may begin
with plants, or with animals, or with human physiology.
If a one-year course is desired, the topics that are
printed in large type in Parts II and III may be used,
and a choice from the chapters in Part I.
For three half-year courses, all the parts may be cov-
ered in full.
If the course in biology begins in the fall (with the
school year), it may be well to study plant biology two
days in the week and animal biology three days until
midwinter; when outdoor material becomes scarce, human
biology may be followed five days in the week ; in spring,
plants may be studied three days and animals two days.
If the use of the book is begun at midyear, it will prob-
ably be better to follow the order in the book consecu-
tively.