292 Non-Isolablc Races. 
sowing. They obviously offer too great a prospect of 
a repetition of the evil. Moreover the seeds of these 
bolters cannot, either by chance or carelessness, get mixed 
up with those of the biennial beets because they ripen 
a year earlier. Thus in every generation an absolutely 
rigid selection of biennial examples as seed-parents takes 
place, and must have taken place as long as the culture 
of beets has proceeded on rational lines. 
Nevertheless these bolters have not disappeared. 
Stringent selection has failed to eliminate them. More- 
over as far as historical data enable us to decide, the 
proportion of bolters remains about the same. In ref- 
erence to this case at any rate we are therefore fully 
justified in stating that selection cannot effect in the 
course of a long period of time what it fails to bring 
about within a few years. 
This belief is widely and firmly held by beet-farmers. 
They are always in search of new means of combating 
this evil ; but the mere selection of biennial beets is con- 
sidered to be without prospect of success. RIMPAU has 
endeavored to attain this end by raising a triennial race, 
by selecting the so-called laggers, i. e., plants which have 
not flowered in the second year ;* but most agriculturists 
content themselves with making the conditions of culture 
as unfavorable as possible to this evil. 2 
These laggers are in a sense analogous to the bolters, 
inasmuch as they have been eliminated by the normal 
process of selection since the time when beets were first 
1 W. RIMPAU, Das Attfschiessen der Runkclrilbcn, Landwirtsch. 
Jahrbiicher, Vol. V, 1876, p. 31, and Vol. IX, 1880, p. 191. By the 
same author, Das Samenschiesscn dcr Ruben, Deutsche Landw. Presse, 
Jahrg. XXI, No. 102, Dec. 22, 1894, P- 94- 
2 A list of the most important papers on the subject is given by 
RUMKER, Die Zuckerrubenzuchtung der Gcgemvart, Blatter fiir 
Zuckerriibenbau, 1894, PP- 22-23. 
