Half Races and Half Curve. 35 



by making r. special curve from plants which exhibit the 

 largest number of abnormalities, or by making a curve 

 from a race bred from such ])lants. But an improved 

 race of this kind remains dependent on selection and high 

 nutrition, and is soon lost if these are withheld.^ One 

 instance will suffice. Achillea Millefoliiun has white 

 flowers, but occasional specimens have red ones. From 

 this I have bred a race wnth red flowers, which some- 

 times even attain the deep red of dark wine. After four 

 years of stringent selection, all the plants in successful 

 cultures were more or less red. But if the plants were 

 grow'n too close or were on poor land, more than half 

 were white, and when I made further sowings witliout 

 selection the proportion of reds rapidly reverted to its 

 original small amount. On the other hand there is on 

 the market the well-known Begonia seniperflorens afro- 

 purpurea Vernon as a constant dark brownish red vari- 

 ety. 



Eversporting varieties revert rapidly under niiniis- 

 selection, but it is seldom possible to eradicate their char- 

 acter altogether as I experienced when working with the 

 adnation of the lateral branches to their main stems in 

 Aster Tripoliuni and Bicleiis grandiflova, and as I shall 

 describe later in greater detail in the case of Celosia cris- 

 tata. (See Part II of this volume.) 



In conclusion, we see that in nature as well as in 

 cultivation (especially in the case of horticultural vari- 

 eties and other anomalies) intermediate forms between 

 the original species and its constant variety are often 

 met W'ith. The two commonest are the half race and the 

 middle race or eversporting variety. The former has 

 a half curve, the latter a bilateral one. Both occur in 



^Vol. T, Part I, § 14, p. 122. 



