232 Non-Isolable Races. 
cago lupnlina, whilst BRAUN has observed them in M. 
saliva. They are well known in T. pratense and T. 
rcpcnSj and WYDLER has recorded 4-foliate leaves in 
Lotus major and Tetragonolobus biflorns. In some suc- 
cessive sowings which I made with Medicago lupnlina I 
found the character to be inherited although in a mod- 
erate degree only, but I have not continued the experi- 
ment. 
But let us return to the crimson clover. The question 
is, what prospects were present at the beginning of the 
experiment, and what may be expected from such ex- 
periments in general ? There are three main possibilities 
to be considered. \Ye may find at the beginning of the 
experiment (See 3 p. 20) : 
1. A race which often exhibits the anomaly in ques- 
tion, and bears it as a heritable character, i. e., an ever- 
sporting variety ; 
2. A half-race with a semi-latent anomaly which is 
only occasionally manifested; 
3. An ordinary plant of the species with the character 
in question in a latent condition. 
In the first case the race already exists and all that 
is necessary is to isolate it ; in the second it may possibly 
be obtained ; in the last there is little prospect of doing so. 
In order to present a clearer idea of the mutual rela- 
tions of these three cases let us examine Tri folium repens 
and T. pratense. That the anomaly is by no means very 
rare is testified in both cases by the popular belief in the 
so-called lucky four-leaved clover as well as by common 
experience. If looked for in a field of clover, or in a 
meadow, or along the roadside, a four-leaved clover will 
be found from time to time. If repeated attempts are 
made to find them they will certainly prove to be rare 
