l/J^^^ 



miner the 



saiBeo 



^y thing more tk:^ 



ifferentiationV' 

 >re or less sal' 



tslorv, when ttefe' 

 ) of charge was : ', 



o 



^ few forms of tie?!:- 



been slow in at i^^ 



icacy of Natural ac 

 ^ to the almost b^i 

 pnistic to the 1# 



phy. 



,gy; vol. i. PP' 'f' 



ore amenable t»;=- 



ons at perif : 

 be made to I* 



In the r^ot^ 



may 



.u. such- 



It^ 



7WB BEGINNINGS OF LIFE. 



Cog 



themselves by the establishment of a moving equili- 

 brium, just as the internal tendencies of crystallizable 

 matter are satisfied (though here to a much greater 

 extent) as soon as it has assumed its appropriate 

 crystalline form. When a certain complexity of struc- 

 ture has been attained, it may be that things are much 



to be by Mr. Darwin, 



\, 



as they have been represented 



Mr. Herbert Spencer, and others. Many organisms 

 may not be prone to vary, unless under the influence 



of 



spontaneously' induced, quasi-accidental changes 



within their own economy, or unless subjected to the 

 disturbing influence of new conditions, or to the more 

 powerful and certain action of Natural Selection, aided 

 by ^use and disuse ' and other agencies. 



Multitudes of facts bearing upon the apparent per- 

 sistence, without variation, of particular species through 

 comparatively long periods, ought to impress us with 

 the possibility of the existence of such a limitation 



to the internal proclivities towards higher 



organi- 



zation which simpler living things display. Some of 

 these facts are alluded to by Mr. Darwin when he 



— *^It has been argued that, as none of the animals 



says^ :— 



and plants of Egypt of which we know anything have 

 changed during the last 3000 years, so probably none 

 have been modified in any other part of the world. The 

 niany animals which have remained unchanged since 

 the commencement of the glacial period would have 

 been an incomparably stronger case, for these have 



] ( 



Origin of Species,' 5th ed., p. 148. 



VOL. IT. 



R r 



