348 
Tricotylous Races. 
position, the proportion of tricotyls (that is to say all 
the aberrant forms of the series) being about 10%. 
DICOTYLS HEMITRIC. TRICOT. 
Or in % 
726 
90.8 
24 
3.0 
46 
5.7 
HEMI-TETR ACOT Y LS 
AND TETRACOTYLS 
4 
0.5 
If we wish to make ordinates for the various degrees 
of cleavage we are met by the difficulty presented by the 
choice of the limits of such arbitrary groups. This diffi- 
Fig. 64. Oenothera hirtella. Intermediate forms between 
the dicotylous seedling (A) and a tricotylous one (G). 
The normal cotyledon has been cut away from each 
plant. Cultivated in 1900. 
culty is partly due to the fact that the stalks of the 
cotyledons continue to grow for some time after the 
cotyledons themselves have assumed their definitive form. 
