1922] SEARS—TARAXACUM 443 
segment and of expression of the following segments. Fig. 8, 
derived from Bonnter’s (2) transplanting experiment, shows in 
leaves of corresponding age a rather uniform teduction of coordi- 
nates throughout, that is, more or less symmetrical reduction of 
leaf size. Numerous observations of the writer upon potted speci- 
mens of the same age, growing side by side but in pots of different 
 . 
Fic. 9 
8, 9.—Fig. 8, showing relatively uniform dwarfing brought about 44 
alpine conditions (right) as compared with lowland. (left); after Bonnter; fig. 9 
showing great increase, particularly in length, produced by saturated (right) as com- 
pared with somewhat dry air (left); after WIESNER. 
sizes, indicate that symmetrical dwarfing (depauperation) does 
occur without greatly influencing leaf form. Under such conditions 
the depauperate specimens produce markedly fewer leaves, and as 
@ consequence may be ready to’ bloom before dissection has pro- 
gressed quite so far as in normal thrifty specimens. Facts of this 
hature must be thoroughly understood before “alpine” forms of 
Taraxacum are pronounced distinct species, or the generalization 
