AND ITS SELF-CONSERVATION. 273 



nothing to forbid, rather there is everything to encour- 

 age, the view that each more complex species of organism 

 arose by development from a less complex species, 

 and this in turn from a species still less complex, and 

 so on until we reach the limit of simplicity in the 

 organic world and discover it to be a primal type of 

 units without specialized organs, and distinguished 

 from inorganic matter only in possessing the charac- 

 teristics of "irritability" and "contractility." And by 

 "irritability" we can scarcely understand anything 

 else to be meant than the most rudimentary phase of 

 the inner quality of self -movement; while "contrac- 

 tility" can hardly mean anything else than the most 

 rudimentary phase of the outer expression of self -move- 

 ment, or life. 



Nor can we, as it seems to me, without ceasing to 

 really think, resist the further logical conclusion that 

 just as all more complex organisms on each inhabited 

 sphere must have descended from a primal type of units 

 that, though organic, were yet not organized; so these 

 latter units themselves arose out of the most complex 

 phase of inorganic matter; which in turn must have 

 developed from the commingling of still simpler ele- 

 ments in the laboratory of nature however impossible it 

 may be to verify all this in a test-tube. 



Thus it appears that we may, with equal truth, de- 

 clare both that Life comes from the living, and that it 

 comes from the not-living. For, while on the one hand, 

 the particular units of the inorganic world which come 

 to be aggregated into an organism are not themselves 

 living units, yet, on the other hand, it is never to be 

 forgotten that they have no existence save as modes of 



