14 INTRODUCTION. 



it is important that he should know its home, its general 

 characteristics, and the treatment the material has re- 

 ceived in case it has been necessary to preserve it in order 

 to have it in good condition at the time the study is to be 

 made. Usually fresh material is highly desirable. Some 

 of this may be kept growing in the laboratory, and local 

 greenhouses will often supply the things needed when 

 they cannot be found in their natural haunts. 



The suggestions as to habitat given at the beginning of 

 the outline upon each topic must be general, and definite 

 knowledge of just where in each locality certain forms are 

 found must be supplied by the instructor and the stu- 

 dents' own observations. 



When it is found necessary to preserve specimens for 

 future use various methods are available. The simpler 

 forms of plants may be preserved entire in seventy per 

 cent alcohol or two to five per cent formalin. Pieces of 

 more complex plants may be preserved in the same way. 

 Some of the Algag may be kept fairly well by drying upon 

 a piece of mica, it being necessary only to moisten the 

 specimens when they are to be used, or by use of the gly- 

 cerin method they may be made into permanent prepara- 

 tions ready for use at any time. Specimens of the higher 

 plants that have ecological value may be made into her- 

 barium mounts by use of a simple plant-press, driers, and 

 mounting-paper. Preservation by means of the more 

 elaborate processes of killing, use of different grades of 

 alcohol, imbedding, etc., will be found fully described in 

 Chamberlain's "Methods in Plant Histology." 



6. Independent work. Finally, it should be said that 

 the greatest benefits will result from the study as outlined 



