322 APPENDIX 



represented as far back as the Lower Cambrian. 

 Independently of the interpretations and explana- 

 tions of this great fact, the numerous types there 

 represented, and the persistence of some of them 

 to the present day, give an almost overwhelming 

 impression of the vast duration of organisms in 

 time. In connection with the supposed slow and 

 gradual process of evolution, this naturally leads to 

 the conclusion that " the whole period in which the 

 fossiliferous rocks were laid down must be multi- 

 plied several times for this later history (that of the 

 higher groups of animals alone). The period thus 

 obtained requires to be again increased, and perhaps 

 doubled for the earlier history." Ordinary geologists 

 naturally stand aghast at such demands, and inquire 

 if they are seriously put forth, and if it would not 

 be wise to hesitate before accepting a theory on 

 behalf of which such drafts on time must be made. 

 The late Edward Forbes once humorously defined 

 a geologist to be "an amiable enthusiast who is 

 happy and content if you will give him any 

 quantity of that which other men least value, 

 namely, past time." But had this great naturalist 

 lived to " post-Darwinian " times, he might have 

 defined a Darwinian biologist to be an insatiable 



