''^^^. altho 



rtant 



respect 



S. 



^^Pounded 



) 





ces 



y Dr. H 



ecular for 

 ological 

 y vital mam. 



armless liviDi 



precisely 

 tinguished bj. ' 



Thej t05 



others— have 



I 



i 



IS IS 



)n. 



definite 



independent 

 the old iifli- 



our 



most ac- 



ar' 



a 



ists have a-- 

 how such 

 of 



■sis 



» 



Us bears'; 

 .1869.P' 



7:^^ BEGINNINGS OF LIFE. 



163 



tion. 



Mr. Her 



bert Spencer writes on this subject in his <^ Principles of 

 Biology.' ' We set out with molecules y he says, ' one 

 degree higher in complexity than those molecules of 

 nitrogenous colloidal substance into which organic 

 matter is resolvable; and we regard these somewhat 

 more complex molecules as having the implied greater 



m- 



instability, greater sensitiveness to surrounding 

 fluences, and consequent greater mobility of form. 

 Such being the primitive physiological units, organic 

 evolution must begin with the formation of a minute 



aggregation of them— an aggregate showing vitality only 

 hy a higher degree of that readiness to change its form of 

 aggregation -which colloidal matter in general displays ; and 



by its ability to unite the nitrogenous molecules it meets 

 with, into complex molecules like those of which it is 

 :onstitote 00c ' composed. Obviously the earliest forms must have 

 it of a higte been minute • since in the absence of any but diffused 



finite formless 

 • of Life °. 



organic matter, no torm but a minute 



nutriment. 



must 



tureless; since as differentiations are producible only 

 by the unlike actions of incident forces, there could 

 have been no differentiations before such forces had 



listinctions of parts like 

 a cell were necessarily 



Hen 



had time to work. 



those required to constitute 



Mr. Spencer here refers to chemical molecules of a very complex 

 naUue, and not to minute visible granules. For an account of the.e 

 complex molecules or 'physiological units' see ' Prin. of Biol.' vol. i. 



P- 182. 



M 2, 



