VITAL ACTION VS. NATURE-ACTION 205 



ties; penetrating its inmost recess, cleansing and heal- 

 ing its secret fabric. 



All the chief architectural forms and structures 

 possible to a one-celled life have doubtless been real- 

 ized; and apparently the best that nature can do within 

 such limits is shown by the minute, unicellular organ- 

 isms called Protozoa. Wherein lie all those limita- 

 tions which prohibit their individual increase in vol- 

 ume, in organization, and vital power, we may only 

 surmise, and need not argue here; but the existence 

 of those limitations we may not question. 



IX. Multicellular Growth 



One of the great innovations in the methods of ani- 

 mal life was the union, or the cohesion, of the offspring 

 of parent cells to form social aggregates, or multicel- 

 lular organisms. This simple innovation opened up a 

 new world of possibilities, produced a larger unit of 

 life, and gave rise to a new order of animal life on a 

 much higher level of organization than before. The 

 very act of union took something away from the old 

 freedom of the cell ; restricted its power of individual 

 action, and conferred upon it new powers, and a new 

 freedom common to all. The groups of cells thus 

 formed had common interests, common dangers, and a 

 common external environment. A new stability was 

 acquired through action and reaction in unison; new 

 powers were gained through sub-division of labor, and 

 by greater economy in the performance of vital pro- 

 cesses. 



Every further increase in the number of cells cre- 

 ated a more and more particular and exacting environ- 



