57 



and reasoning draw his own conclusions regarding the functions 

 of organs and their adjustment to environment. The suggestions 

 and appliances for conducting the various experiments will be 

 found highly satisfactory. While the experiments are simple and 

 easily prepared, attention is directed to the performance of each 

 demonstration and to the proper construction of the apparatus. 

 The author's device for the demonstration of the evolution of 

 oxygen by green plants in sunlight and the relations of the plant 

 to the air, as shown in Fig. 64, is a typical demonstration, and 

 illustrates the author's care in the manipulations, and in setting 

 forth scientifically complete experiments. 



One of the most commendable features of the book is the con- 

 tinued emphasis given the more manifest structures and functions. 

 The plant is constantly treated as a living organism responsive 

 to the forces playing upon it and always showing a purposeful 

 reaction. This feature is worthy of more than passing commen- 

 dation. It not unfrequently happens that the student loses sight 

 of the nature of the reaction in the stress laid upon its exact meas- 

 urement by ordinary methods, and the efficiency of elementary 

 courses is frequently seriously interfered with by the mathemat- 

 ical exactness required in the prosecution of the work. 



It seems to us that the author is very happy in the introduc- 

 tory portion of the subject by the consideration of growth. While 

 this procedure may violate the logical arrangement of the subject 

 yet it plunges the student at once in the first day of his course 

 into a series of observations and experiments easily made which 

 are sure to awaken the keenest interest. It is, in fact, immaterial 

 for the time being, whether he may be acquainted with the inti- 

 mate structure of the growing organs or not. Ample opportunity 

 for acquiring such information soon follows. The advantage de- 

 rived from giving the student a chance to gain some accurate in- 

 formation of his own at first hand upon a familiar phase of the 

 activity of the plant is obvious and the training received will 

 enable him to appreciate better what might be termed the more 

 fundamental portions of the subject in the work that follows. 



C. C. Curtis. 



