CHAPTER II. 



OF LIFE, WHAT IT CONSISTS OF, AND THE CONDITIONS 

 OF ITS EXISTENCE IN A BODY. 



Life, said M. Richerand, is a collection of phenomena which succeed 

 one another for a limited period in organised bodies. 



He should have said, life is a phenomenon which gives rise to a 

 collection of other phenomena, etc. ; for it is not these other phenomena 

 that constitute life, but they are themselves caused by Ufe. 



A study of the phenomena resulting from the existence of life in a 

 body provides no definition of life, and shows nothing more than 

 objects that Ufe itself has produced. The line of study which I am 

 about to follow has the advantage of being more exact, more direct 

 and better fitted to illuminate the important subject under considera- 

 tion ; it leads, moreover, to a knowledge of the true definition of life. 



Life when studied in living bodies is exclusively due to the relations 

 existing between the three following objects : the parts of the body 

 adapted for containing Uquids, the contained liquids moving in them, 

 and the exciting cause of such movements and changes as are carried 

 out. 



Whatever efforts we may make by the most profound thought and 

 meditation to decide as to what Ufe consists of, we shall necessarily 

 be compelled to fall back on the principle just enunciated as soon as 

 we pay attention to the teaching of observation on the matter ; in 

 fact, Ufe consists of nothing else. 



A comparison drawn between Ufe and a watch in active movement 

 is inadequate, to say the least of it ; for in the watch there are only 

 two main points to consider : (1) the wheels and machinery of 

 movement ; (2) the spring which by its tension and elasticity keeps 

 up the movement so long as that tension continues. 



But in a Uving body, instead of two chief points for study, there are 

 three : (1) the organs or supple containing parts ; (2) the essential 

 contained fluids which are always in motion ; (3) lastly, the exciting 



