386 THE CANADIAN NATURALIST, [Vol. ix. 



the Life Question." After a few preliminary remarks lie 

 continued : 



" What now are we to understand by the word ' Life ' in 

 this discussion ? A noteworthy parallel is disclosed in the pro- 

 gress of human knowledge between the ideas of life and of force. 

 Both conceptions have advanced, though not with equal rapidity, 

 from a stage of complete separability from matter to one of 

 complete inseparability. Life is now universally regarded as a 

 phenomenon of matter, and hence of course, as having no separate 

 existence. But there still exists a certain vagueness \u the 

 meanins: of the term ' Life.' Two distinct senses of this word 

 are in use : the one metaphysical, the other physiological. The 

 former, synonymous with mind and soul, at least in the higher 

 animals, has been evolved from human consciousness ; the latter 

 has arisen from a more or less careful investigation of the phe- 

 nomena of living beings. It need scarcely be said that it is in 

 the sense last mentioned that the word '• Life " is used in science. 

 The conception represents simply the sum of the phenomena 

 exhibited by a living being. 



'' Moreover, the progress which has been made in the solution 

 of the life-question has been gained chiefly by investigation of 

 special functions. But the functions of a vital organism are 

 themselves vital. What then is the meaning of ' vital ' as 

 applied to a function ? Fortunately the answer is not difficult. 

 ' Life,' says Kiiss, the distinguished Strasburg physiologist, ' is 

 all that cannot be explained by chemistry or physics.' Guided 

 by such a definition the work of the physiological investigator 

 is simple. He has only to test each separate oparation which he 

 finds going i n in the organism and to declare whether it be 

 chemical or physical. If it be either, then since e»ich function 

 is non-vital, the entire organism must be non-vital also. Hun- 

 dreds of able investigators, provided with the most effective 

 appliances of research, are now in full cry after the life principle. 

 Naturally, a vast amount of collateral knowledge is accumulated 

 in the process. The quantitative as well as the qualitative re- 

 lations of things are fixed, and many important facts are 

 collected. 



" As a first result of recent work, the living organism has 

 been brought absolutely within the action of the law of the Con- 

 servation of Energy. Whether it be plant or animal, the whole 

 of its energy must come from without itself, being either absorbed 



