582 



THE BEGINNINGS OF LIFE. 



the hairy coverings of sheep^ goats^ dogs, cats, horses 



and other animals 



1 



and 



Many of such instances cited by Mr 

 other writers, abundantly testify to the fact that 

 changes are frequently induced, both amongst animals 

 and plants, 



alterations in the conditions of life. 

 And these changes are of course liable to become 

 intensified in the course of time. On the other hand 



we know quite well that other animals and plants 

 which happen to have a less impressionable consti- 

 tution, may range over large portions of the world 

 without undergoing any appreciable modification 2. 



Internal Causes of Change and ^Progressive 



y 



Development^ . 



The divergence of opinion to which we have already 

 referred is, however, as nothing compared to that 



■ * 



which obtains concerning the existence or non-exist- 

 ence of certain ^principles' or tendencies inherent in 

 the organism itself, and leading, in the main^ to an 

 increasing complexity of organization. 



■ r 



The existence of such ^principles' or tendencies 

 has been frequently affirmed, though even more fre- 

 quently denied, either implicitly or explicitly. 



^ ' Animals and Plants under Domestication/ vol. ii. p. 378. 



2 Similarly we find that the majority of crystals maybe exposed to the 

 incidence of a considerable change in conditions, without producing or 

 necessitating molecular rearrangements, though others, such as mercuric 

 iodide, are most sensitive to changing influences, under which they 

 are apt to assume not only changes of form but also complete altera* 

 tions of colour. (See p. 82.) 



tH^ 





.t 



i 



\ 



liate 



iffifl 



orig 



or r 



^ \ 



I 



i been sp 

 few fii^st c 



Eras 

 ofCr' 



scia 



11 3 



I 



s 



1 



I 



I 



have suff 



the long laps 



)«er 



) 



life that have < 

 Prof. 



( 



toe express 



ed 



ioa of living n 



I 



to this has b 



to inter: 



in certain preoK 

 others) of 

 «fMan^. But 



workin: 



I 



Zoon 



\ 



It 



, .r^"-")- of the 



. ^ °f Spec 



•^K innate 



^} tend 

 ''«« and 



capa 

 '0 e\Tolv 



%, 



foute of 



( 



I 



C 



f'N 



« of V 



aianif. 



'"ttati 



5ces 



esi 



!^io 



ined 



Hot 



1 



^Kv 





