52 DARWIN AND NATURAL SELECTION 



bead of protoplasm, although it may be associated 

 with that bead, and the arguments which may be 

 used concerning it are of quite a different order 

 from those which can be used about the " bio- 

 phores." 



It is open to the opponents of this view to say 

 that the vitalistic hypothesis is unprovable, and 

 that we can know nothing about the matter, and 

 that, in fact, is the attitude of despair assumed by 

 some, at least, of them. Those who believe that 

 the existence of such a force is capable of proof 

 by adequate arguments will find ample corrobor- 

 ation of their view in the closely argued pages of 

 Driesch's work just alluded to. 



Returning to the variations which occur in the 

 world of nature, we shall find that some of these 

 are small and some greater that is to say, that 

 the departures from what may be considered to 

 be the normal type of the form in question are 

 slight or are considerable. Much controversy rages 

 at present as to whether both kinds of variation 

 may be inherited and, if not, which of the two 

 affords the means of transformation or evolution. 

 Darwin himself seems to have pinned his faith to 

 the smaller changes, though there is some ambigu- 

 ity in his works on the subject, and consequently 

 some difference of opinion amongst his present- 

 day commentators as to his real meaning.* 



On the other hand, de Vriesf has put forward 

 a theory which has been tentatively advanced by 



* On this point, see Datwin and Modern Science, pp. 70, 71. 

 t See his work, Species and Varieties (1905), of which an account 

 is given in a later article. 



