APPENDIX II 365 
Ecology. — It will not usually be found worth while to undertake 
ecological studies unless considerable field work (or at any rate, out- 
of-door work) can be done. It is almost useless to discuss adapta- 
tions to environment unless the environment itself is as much under 
observation as are the plants that live in it. A good deal of ecology 
can be interwoven during trips undertaken mainly for the purpose of 
getting acquainted with the local flora and collecting for the school 
museum and laboratory. The first requisite for teaching the rudi- 
ments of ecological botany is to impress upon the student the reality 
and severity of the struggle for existence among plants, since compe- 
tition must exist in order to make adaptation necessary. Any such 
studies as are suggested in Sects. 154-156 of the Manual may be 
undertaken for this purpose. Even boxes of seedlings grown in a 
Wardian case or on a sunny laboratory window sill will help to show 
the effects of competition. 
Many ecological topics, such as field studies of parasitism, of insect 
pollination, of ecological classes, or of plant formations may profitably 
be assigned as voluntary work to single students or small groups 
observing together. 
INTERPRETING RESULTS OF LABORATORY WORK 
Most of the results of physiological experiments can be judged by 
reference to the statements of Pfeffer, Detmer, and other authorities, 
and morphological and histological work may be reviewed by com- 
parison with the statements and the figures found in such general 
treatises as the Strasburger text-book, in the Strasburger-Hillhouse 
Practical Botany, and in special works. But the teacher will find it 
indispensable to keep for reference a full illustrated set of notes of 
the year’s work, and to add to this year by year as additional types 
are studied or new results are obtained in any of the experiments 
performed as demonstrations or by the class. 
