364 ESSENTIALS OP BOTANY 



BIBLIOGRAPHY 



In this place only a few suggestions will be given to supplement 

 the bibliography of the Manual. The books which are there double- 

 starred are among the most important for reference. Some, how- 

 ever, like Pfeffer's Physiology of Plants, are very expensive, and such 

 briefer works as Peirce's Text-Book of Plant Physiology (Henry Holt & 

 Co., New York), or Green's Introduction to Vegetable Physiology (P. 

 Blakiston's Sons & Co., Philadelphia), may be bought as an alter- 

 native. It is often found difficult to identify even the genera of algse 

 and fungi which are encountered in collecting. For fresh-water 

 alga3 and some aquatic fungi no book is more useful than Whipple's 

 Microscopy of Drinking Water (John Wiley & Sons, New York). 

 Many fungi can be identiiied by means of Massee's Text-Book of 

 Fungi (The Macmillan Company, New York). 



SPECIAL TOPICS FOR STUDY 



Economic Botany. — Few subjects will be found to interest most 

 classes more than some of the topics of economic botany. These 

 can often be assigned for optional work, for which credit may be 

 given. The topics to be suggested would vary much, according to the 

 environment of the school. In agricultural districts reports on local 

 conditions as regards use of improved seed for farm and garden 

 crops, on trials of new economic plants, on tree-planting and the 

 management of wood lots, would all prove valuable subjects for 

 discussion. City high-school classes can find fewer opportunities 

 for reports and investigations, but some practicable topics are the 

 comparative value of various species of shade trees and the insect 

 enemies of each species, the sources of the winter flower-supply and 

 modes of forcing flowers, the examination of the gross and histological 

 characteristics of woods and the classification of these by families 

 and according to their structural likenesses, the study of commer- 

 cial fibers, the histological examination of vegetable foods (such as 

 starches) and of powdered drugs. Many interesting and valuable 

 studies of the relation of microscopic organisms to fermentation and 

 decay may be made with simple apparatus, as described in Conn's 

 Bacteria, Yeasts, and Molds in the Home (Ginn & Company). 



