48 LIFE AND DEATH. 



pletely constructed organized being, perfected in its 

 form. The explanation of the working of this con- 

 stituted machine cannot be complete until we take 

 into account the harmony and the adjustment of its 

 parts. 



Harmony and Connection of Parts : Directive Forces. 

 These constituent parts are the cells. We know 

 that the progress of anatomy has resulted in the 

 cellular doctrine i.e., in the two-fold affirmation 

 that the most complicated organism is composed of 

 microscopic elements, the cells, all similar, true 

 stones of the living building, and that it derives its 

 origin from a single cell, egg, or spore, the sexual cell, 

 or cell of germination. The phenomena of life, looked 

 at from the point of view of the formed individual, 

 are therefore harmonized in space ; just as, regarded 

 from the point of view of the individual in formation 

 and in the species, they are connected in time. This 

 harmony and this connection are in the eyes of the 

 majority of men of science the most characteristic pro- 

 perties of the living being. This is the domain of vital 

 specificity, of the directive forces of Claude Bernard and 

 A. Gautier, and of the dominants of Reinke. It is not 

 certain, however, that this order of facts is more 

 specific than the other. Generation and development 

 have been considered by many physiologists, and 

 quite recently by Le Dantec, as simple aspects or 

 modalities of nutrition or assimilation, the common 

 and fundamental property of every living cell. 



The Work of Claude Bernard. Exclusion of Vital 

 Force, of Vital Cause, oj the " Caprice" of Living Nature. 

 It is not, however, a slight advance or inconsider- 

 able advantage to have eliminated vitalistic hypotheses 

 from almost the whole domain of present-day physi- 



