BIOLOGY IN EDUCATION-. 5 



plant life, leads us to deal with problems which, for example, 

 belong more or less completely to chemical science. The 

 nature of foods, the reaction of animals and plants upon 

 the atmosphere nay, the very differentiation or separation 

 of the one series of living organisms from the other, and the 

 nature of life itself, are all so many questions in the dis- 

 cussion of which a knowledge of chemical science is abso- 

 lutely necessary. The investigation of the products of plant 

 or animal life, and of the functions whereby these products 

 are produced, render the chemical aspects of both botany 

 and zoology an essential study for the modern biologist. 



In a less important but still feasible manner may the 

 studies of the natural philosopher or physicist be brought 

 into the field of biological inquiry. The characters of the 

 inorganic, as distinguished from the organic, world ; the 

 investigation of phenomena of such importance in the life 

 of plants and animals as endosmose and exosmose; the 

 relations which nerve-action bears to electrical and magnetic 

 forces ; and even the comparatively simple study of how a 

 fish rises or sinks in the water through the agency of its 

 ''swimming-bladder" or "sound," are so many processes 

 in the satisfactory elucidation of which, an acquaintance 

 with at least the principles of natural philosophy will prove 

 of great service to the biologist. The consideration of 

 animal mechanics may similarly relate the domain of mathe- 

 matical science to that of biology ; and with geology and 

 mineralogy the science of life possesses relations of a very 

 intimate kind. One of the most fascinating departments of 

 biological inquiry is unquestionably that of investigating the 

 conditions under which life existed in the past. Without 

 a knowledge of the distribution in time of living organisms, 

 as already remarked, the biologist's information would be 

 very far from satisfactory or complete ; and an acquaintance 

 with the facts and laws of geological thought is very neces- 

 sary in the active practice and work of the student of 

 life-science. 



Thus the study of life-science may be shown to relate 



