action / 



THE BEGINNINGS OF LIFE. 



577 





nt 



m 





'W 



e 



r- 



direct agencies recognized by others^ that he almost 

 neglects them as independent producers of variation 

 and gives to the special agency a general range and 

 applicability^. 



■^^iQg to deiini 



net 



nite 



<^onsideratioDj' 

 ' i for A^<7fw^/ 



Influence of Change tn 'External Conditions^ 



I * 



If we take the three modes already referred to, or 



any others, by which variations in the form or structure 



of animals and plants are initiated, we find that in 



each alike, if the change is to be a permanent one, 



the principle of inheritance must come into play. It is 



mj motlijicatm nj: therefore only amongst the ^ primary causes ' of varia- 



licized seems foil' tion that any room for difference exists. Thus we 



distinction te; ^^7 have: — (i) some altered incidence of external 



^oas and com^k ii, 



^^Sy hut h 



as m ii 



•vet 



of already G 



ction as a 



1 



xMr. Darwin; i 

 must have bsffl' 



in fact, atta* 



;elcctIon as a p- 



influence 



of 



f we 



simply 



. lice tfl^ ." . 



use 



' ..'I 



■hat con 



. Mr. 



pan^i"' 



bs< 



1^ 



rt 



of 50^^ 



w 



riters 



^'. 



If 



iS6S. 



! 



forces directly bringing about an altered internal 

 action in the complex moving equilibrium which the 



r 



organism represents, and the perpetuation of such 

 alteration 



inheritance, under the persistence of 

 similar conditions ; (3) the gradual induction of some 

 altered structure by modifications initiated in the func- 

 tional activity (indirect influence of conditions) of 

 some part of an organism, which alteration is similarly 

 perpetuated; and (3) the perpetuation and intensifi- 

 cation by inheritance, through several generations, of 

 some one or more out of the many individual differences 

 which are always manifesting themselves in the different 



^ Although of late Mr. Darwin has appeared more disposed to limit 

 the supposed influence of Natural Selection. (See note 3 of next page.) 



VOL. II. 



Pp 



