IM ATHEWSONi 



PRACTICAf. AND SCIENTIFIC BIOLOGY m 



the average person. Rather, instead of studying so many trees 

 take up other practical phases like stem-fiber products, stem- 

 extractives, and edible stems. 



The same method is applicable as well in zoology. One of our 

 most-prized lessons in evolutionary biology is the one on frog 

 embryology. If we follow this up with some lessons on fish 

 hatchery and state and national work on fish preservation, the 

 development of an animal from egg to maturity connotes more, 

 even to the dull and average minds of which Professor Ganong 

 speaks than it otherwise would. 



Some typical calculations showing the relations of birds as 

 insect and rodent destroyers are always interesting in connection 

 with the study of structure and function in birds, but to trace out 

 such economic relations in loo birds with one's class, as suggested 

 by Dr. Hodge, would be a weariness to the flesh. Rather call to 

 mind by a few specific cases the appalling destruction of bird life 

 in this country, and the means for checking such destruction. 



The things that the average person is to learn from a study of 

 insects are hardly to be deduced from a study of 150 insects. 

 Professor Ganong is c^uite right in assuming that most people are 

 not as mtich interested in the economic relations of 1 50 insects as 

 they are in the cell-theory of biology, for example. Nevertheless 

 if we study with our pupils the economic relations of insects as a 

 class, and of a few typical examples, we may still have ample 

 time to introduce into our courses such illuminating ideas as are 

 represented by the cell-theory. 



Chester A. Mathewson. 



High School of Commerce, 

 New York City. 



