Examples of Constant Races. 
87 
vulgaris tricalcarea, 1 of many glabrous forms like Lych- 
nis vespertina glabra, of thornless types like Datura Stra- 
monium incnnis, 2 etc., all of which I have tested per- 
sonally. Space does not permit of the compilation here 
of anything like a complete list of constant varieties. 
mm 
Fig. 12. Melilotus coendca monophylla. Each leaf consists 
of a single blade but is more or less deeply incised. One 
of the lateral leaflets in the middle leaf on the right of 
the figure appears to be quite free. A, a bract from the 
inflorescence; here the leaves are least incised. 
1 J. H. WAKKER, Linaria rulgaris, Nederl. Kruidk. Archief, 1889, 
with plate X. 
2 See Fig. 5 on page 31 of Vol. I. 
