476 Syncotyloiis Races. 



towards the middle of the base Hne, the sweep of the 

 curve would obviously have been a still more gradual 

 one. We see, therefore, here as elsewhere, that the inter- 

 mediate race or eversporting variety is far more suscep- 

 tible to selection than the half race. 



§ II. niPROVEMENT OF A HEMT-SYXCOTYLOUS RACE. 



Like tricotyly, I regard syncotyly as a single ele- 

 mentary character the external manifestation of which 

 is subject to fluctuating variability. Completely fused 

 cotyledons, which are the type occurring most abundantly 

 (see Fig. 98), constitute the normal or typical structure, 

 whilst the lower degrees of fusion and the bilateral unions 

 are the minus and plus variants of the same series. 



One of the most important problems in the theory 

 of mutation is to bring together the various expressions 

 of the same elementary character in each particular case. 

 The delimitation of such groups is often clear at once, 

 but often it can only be reached by the actual observa- 

 tion of the process of mutation. Still, the question is 

 obviously a fundamental one, for our whole conception 

 of affinities must rest on it, both in the question of species 

 and in that of hybridization. We must therefore seek for 

 methods which will lead to a solution of this problem. 



AVith regard to the present case we may start from 

 the following discussion. If the hemi-syncotyls and 

 amphi-syncotyls were representatives of distinct elemen- 

 tary characters, we should expect to be able to isolate 

 the corresponding races. The amphicotyls are too rare 

 and too difficult to cultivate, on account of the disturb- 

 ance in the growth of the plumule, to offer much prospect 

 of success. Hemi-svncotvls, on the other hand, are well 



