398 Tricotyloiis Races. 



fact that the goal l)ecame ever more obviously unattain- 

 able; but nothing I did was of any avail. The half races 

 remained half races, and the prospect of attaining an 

 intermediate race is no greater now than it was at tlie 

 beginning.^ 



I shall proceed now to the description of my two ex- 

 periments. 



Amarantus spcciosus (Fig. 83). In 1889 I had a 

 tricotylous and a hemi-tricotylous specimen of this fine 

 garden plant, w^hich usually attains a height of from 

 VA to 2 meters. They flowered together, but far removed 

 from any other specimens of the same genus. ^ I har- 

 vested the seeds separately, but only sowed those of the 

 hemi-tricotylous plant. This had a small comb-shaped 

 extension of the summit of the raceme as is showni in 

 Fig. 83, and as it afterwards often occurred in this race. 

 Its seeds gave rise to four tricotyls and one hemi-tricotyl 

 amongst 110 seedlings, that is, a proportion of about 

 4.5%. The degree of inheritance therefore proved to 

 be greater than in most of the other half races investi- 

 gated (^4). The culture was, however, unfavorable, 

 since only one hemi-tricotylous plant could be brought 

 to flower, and since therefore a number of atavists had 

 to be cultivated with it as a precautionary measure: but 

 I only saved the seed of tlie hemi-tricotylous plant. This 

 produced 6 tricotylous and 5 hemi-tricotylous seedlings 

 amongst 250, that is, about 4.5% or the same amount 

 as in the previous generation. This time, however, T 

 could plant out the aberrant forms only and I managed 

 to keep the majority of them alive. Only one, however, 



' Mutations must, nevertheless, have external causes, and these 

 must be found some day, but perhaps by some other means. 



^ Amarantns spcciosus is regarded by some authors as a sub- 

 species of A. paniculaliis. 



