THE AMERICAN NATURALIST [Vol. LV 



The presence of the characteristically masculine comb 

 and wattles in the male Sebright which is otherwise 

 henny, shows that another factor similarly detachable 

 governs their development. 



To the breaking up of large compound factors the pro- 

 duction of intermediate t>^es, such as occur among the 

 color-varieties of plants, is in all likelihood due. The 

 sweet pea and the snapdragon have now an innumerable 

 series of such color-forms which may be represented as 

 having arisen by the disintegration of the various antho- 

 cyanins. That, at least, is the simplest way in which 

 their origin can be conceived. 



To the final result many qualifying elements contrib- 

 ute, and these may naturally be separate entities. But 

 change in the amount of the same coloring material, and 

 diminution in the mere extent of its distribution, are 

 common features of these graduated series. As the cul- 

 tural development of the species progresses, more and 

 more of these quantitative intermediates appear, and are 

 selected until a practically continuous series is produced. 

 Although the interrelations of the whole series can be 

 represented by a factorial scheme, the assumption that 

 each of these factors had an aboriginal individuality ap- 

 pears gratuitous. In AnlirrMnum, for instance, the 

 ordinary self-colored flower segregates as a single unit 

 from the white. But there are ''Delila" forms having 

 the ''face" colored and the "throat" white. Another 

 variety has the "lip" colored and the peripheral parts 

 white and to this again there is an almost exact counter- 

 part in which the peripheral areas are colored and the 

 lip nearly white, and between these again there are fur- 

 t1ier intergrades. Apart from factors modifying its 

 ijuality, the color of the whole corolla, segregating as a 

 single entity from the white, would without hesitation be 

 rei)resented as depending on a single factor. Subse- 

 quent experience that tlii> entity cmu break up into an 

 indefinite number of fi-nctioii- not evidence that the 

 original representation \va> wrong. Tliis reasoning ap- 

 plies to a great range of phenomena. 



