CHAP, iv.] OF LIFE. 33 



lated, transforms itself in a thousand ways. These transmuta- 

 tions of movement take place also naturally in living beings, 

 and the impulsions, so complex and varied, of the molecules 

 transmit themselves to the different organic apparatus, producing, 

 here the generation of new anatomical elements, there, the 

 movements of totality of the living substance, elsewhere the 

 nervous phenomena of consciousness, everywhere a certain 

 elevation of temperature and, doubtless, electric phenomena. 



It has been said, and may be admitted as a general principle, 

 that the animal world lives at the expense of the stores of matter 

 and of movement accumulated by the vegetal world. We 

 shall have to show, at a future time, what amount of truth there 

 is in this generalisation. We content ourselves, at present, with 

 remarking that these vegetal accumulations are formed under 

 the influence of solar radiation, that is to say, of the vibrations 

 radiated by the central star of our planetary system, and that, 

 consequently, the dynamic solar source is the great reservoir of 

 force, the great motive power, which gives the impulse to the 

 vital movement, and sustains the impulse given. 



And now can we define life 1 For that purpose it will evi- 

 dently be sufficient if we summarise the preceding facts into as 

 clear, and at the same time as brief, a formula as possible ; 

 for it is not our intention to pass in review the very numerous 

 definitions which have been given of life, long before its pheno- 

 mena were scientifically analysed. 



The definition now most commonly adopted in France is that 

 given by Blainville : "Life is a twofold movement, at once general 

 and continuous, of composition and decomposition." This defini- 

 tion, as H. Spencer judiciously points out, 1 is at the same time 

 too comprehensive, and not comprehensive enough. It is too 

 comprehensive, because it is applicable to that which occurs in 

 an electric pile or in the flame of a wax taper, as well as in the 

 primordial nutritive phenomena ; it is too restricted, because it 

 leaves out the highest, the most delicate vital activities, the 

 1 Principles of Biology, voL i. 



D 



