'i^ 



l/fi^_ 



crcasi 



mi 



^ of life 



lifo 

 Or 



cial 

 bcli 





no 



period 



\ 



leve in 

 It, but is 



V 



SQ IP- 



% 



r 



Iccti 



ion or 



sur?itii 

 ■^ ^'ariationsoi"* 

 nature occasi/ 



len preserved; I 



t at all incoffiE 



\ 



v.. 



I 



re mentioneA 

 ent reasons 



lU 



1^1 



r organisms are 



)\ver organisms ' 

 interesting f 



12 \^' 



ords^^: 



■?. ' 



J' 



find good ^^^ 

 of stability 



#^ 



acluding^r: 



1 soon 



/' 



1 



11 be slo*; 



cause 



has 



m 



their i^^.^^^^,'- 



is 



ucb ch^"^ 



TJIE BEGINNINGS OF LIFE. 



6ii 



a short time in action, the modification generated will 

 be evanescent ; for concluding that a modifying cause, 

 acting even for many generations, will do little towards 

 permanently altering the organic equilibrium of a race ; 

 and for concluding that, on the cessation of such cause, 

 its effects will become unapparent in the course of a few- 

 generations.' 



The question, therefore^ as to the mode of explana- 

 tion of the existence of very simple organisms at the 

 present day, merges in an almost insensible manner 

 into that concerning the explanation of the existence of 

 so-called Persistent Types. 



The Foraminifera, for instance, are organisms which, 



?lopmentj wb: from the absence of all sexual distinctions, and from 



the extreme simplicity of their body-substance, ought, 

 in spite of the notable complexity of the shell-like 

 structures which many of them inhabit, undoubtedly 



to rank 



amongst 



the ephemeromorphs. The ani- 

 mal substance of these organisms differs little from 

 that of Amoebge, Arcellini€^ and other simple Rhizo- 

 pods^ and, moreover, we are distinctly informed by 



# 



Dr. Carpenter that any such definite assemblages of 

 individuals as are usually included under the word 



'species' do not 



xist amongst them. 



He says : 



'The range of variation is so great amongst Foramt- 



^fi 



ry 



^ 



differential charac- 



ters which systematists, proceeding upon the ordinary 



/^i 



also those upon 



which the greater part of the genera of this group have 



R r 3 



