96 THE THEORY OF MUTATIONS 



what we now call elementary species " (p. 13). 

 Those desirous of examples of what is here de- 

 scribed may be referred to de Vries' account of 

 the different varieties of elementary species of 

 Viola.* It is possible, so it has been argued, that 

 these " smaller species," or " elementary species," 

 or " constant varieties " are " incipient Linnaean 

 species, which, by further variations of the same, 

 or of other sorts, may end by giving rise to true 

 species. A genus composed of several species might 

 be formed in this way, and then, if each species 

 were again broken up into a number of new 

 groups, each such group would now be recognized 

 as a genus, and the group of genera would form 

 a family, etc. The process continuing, a whole 

 class or order, or even phylum, might be the result 

 of this process that began in a single species. "f 



At any rate we can see for ourselves that, as 

 Bateson puts it, " the forms of living things are 

 various and, on the whole, are discontinuous or 

 specific " (p. 3) ; and what we have now to discuss 

 is how, assuming transformism to be the explana- 

 tion of the state of nature as we see it, this dis- 

 continuity came about. Was slight change added 

 to slight change until at last a new " elementary 

 species " stood revealed ? or did each " element- 

 ary species " suddenly make its appearance as a 

 definite and complete entity ? How, in other 

 words, was differentiation introduced into the 

 series of which the species we are now considering 

 may be regarded as, for the moment, the last 

 term ? All that we know, as Bateson points out, 



* pp. 38 et seq. t Morgan, p. 85. 



