508 SCIENCE PROGRESS. 



organisms. While satisfying the mind as being an intel- 

 ligible, though unimaginable cause, it tends neither to stifle 

 nor to limit inquiry. Nothing here advanced tends to de- 

 preciate the cell-theory, nor any other physical hypothesis of 

 practical utility. Let the essence of each living creature be 

 an active, immaterial principle of individuation, it remains 

 not a whit less true that the various cells of the tissues are 

 conditions sine qua non of growth and that "the whole 

 organism subsists only by means of the reciprocal action of 

 its single elementary parts ". 



This conception being accepted a practically inexhaust- 

 ible field of research will none the less ever remain open 

 for the discovery of the successive hierarchies of material 

 agents, which intervene between the immanent prime cause 

 of each organism's activity and the ultimate manifestations of 

 the latter. The structure of the cell, its nucleus, its more 

 minute structures and the interactions of the many parts 

 which yet remain to be discovered, are in no way less 

 interesting to one who accepts the view here advocated 

 than to him who is unable or unwilling to rise above the 

 imagination of material particles exclusively. 



St. George Mivart. 



