210 The Ottawa Naturalist. [Mar. 



of the principles that will guide us in attaining the end for which 

 we are working, that I have chosen this as the subject of rny 

 address this evening. I will endeavour to indicate, somewhat 

 brieflv I am afraid, a few of the problems which depend for their 

 solution upon the results of biological investigation. As His 

 Excellency Earl Grey truly said in his address to the Conserva- 

 tion Commission on the occasion of its first meeting: "The 

 future well-being of Canada depends upon the loyal acceptance 

 by its people of the principles which aim at the profitable, and 

 scientific development and conservation of your natural re- 

 sources. I recognize that the future prosperity of Canada 

 depends upon scientific research and upon the efficient appli- 

 cation of the results of that research to the industrial and 

 physical life of the people." 



We must take a broad view and regard the problem 

 from its aesthetic and ethical side as well as from its practical. 

 We are a practical nation, but there is a growing danger that 

 success and material prosperity may be taken as synonymous 

 with, and as the criterion of, a national happiness, than which 

 there is no mistake more profoundly erroneous. 



The Soil. 

 The greatest need of man is food, and his food, direct!}^ or 

 indirectly, is a product of the soil. On the producing power of 

 the soil, therefore, the lives of the people as well as the future 

 existence of the nation depend. It will be understood then how 

 important a question the conservation of this great producing 

 power, the fertility of the soil, is to so essentially an agricultural 

 nation as Canada. The suppl)^ of the organic constituents of the 

 food of plants is inexhaustible, but this is not the case with the 

 inorganic chemical constituents of the plant food nitrogen, 

 potassium and phosphorous : and when we speak of the conserva- 

 tion of the essential elements of the soil we refer to these elements, 

 of which the most important is nitrogen. Since 1660 this element 

 has been regarded as one of the sources of the fertility of the soil, 

 and after many years of careful inquiry we have come to the con- 

 clusion that the fertility of the soil can be attributed to no one 

 cause: nevertheless, the available nitrogen is one of the chief 

 factors in this fertility. It will naturally be inferred that this is a 

 question of a chemical nature which does not concern the 

 biologist. The day has passed when one branch of science can 

 stand aloof from the rest, as the history of the present problem 

 will indicate. In 1886, Hellreigel and Wilfarth discovered that 

 the nodular growths found on the roots of the leguminous plants, 

 such as peas, clover, alfalfa, etc., contained bacteria which were 

 capable of drawing nitrogen from that large reservoir of other- 



