No. 509] THE CATEGORIES OF VARIATION 273 



of rays was raised to about 34, "a figure never reached 

 by the grandiflora parent." 



The unbiased reader who has carefully followed the 

 account of the production of this double flower can 

 scarcely escape the feeling that the interpretation of the 

 facts according to the mutation theory is at times some- 

 what strained. The starting point of the whole process is 

 the selection of fluctuations. Now and then the selection 

 of a somewhat more pronounced variation was made ; but 

 the so-called mutations had very small and weak begin- 

 nings, and De Vries is uncertain just where they occurred 

 and even suggests that they may have been built up grad- 

 ually! The selection of fluctuations seems to have had 

 the effect of inducing variations of greater stability, if 

 not greater extent, in the same direction. It is not unrea- 

 sonable to suppose that the appearance of florets with 

 ligulate corolla on the disk is due to the same factors 

 which cause the increase in the number of ray florets, and 

 the variation may be in reality not so discontinuous as 

 it seems. In fact we are ignorant of the stability or the 

 real discontinuity of many of the steps in advance towards 

 the production of the double flower. If a mutation can 

 make its appearance as an extra ray floret in one case, 

 and by the occurrence of two or three ligulate corollas 

 on the disk of a few flowers of the plant in another, and 

 if both these characters can be increased by selection until 

 they reach a stable condition that is far more highly 

 developed than their original one, the facts do not lend 

 much support to a theory of the saltatory origin of 

 species. Rather they would indicate that species have 

 been formed along lines determined by selective processes 

 much in the same way as Darwin conceived them to be. 



By a similar method of selection Burbank has produced 

 a scarlet variety of the California poppy, Eschsclioltzia 

 calif ornica. He noticed one flower with a fine scarlet line 

 on one petal. From the seed of this plant other poppies 

 with scarlet lines were produced, but only to a slight 

 extent. After selection was practised for some years 



