276 BOTANICAL GAZETTE [OCTOBER 
diminutions of the Jaefa type may, at least in part, be considered 
as influenced by neighboring characters. The combination 
O. cana nanella has occurred in many instances during these experi- 
ments, either from the crosses of O. cana with the dwarfs of my 
race, or as occasional mutations in other cases. A repetition of my 
experiments, in which O. cana nanella would be chosen for ferti- 
lization by the other species or mutants used, would probably give 
the material to decide these questions. 
Putting aside all of these more special considerations, we may 
conclude that O. cana behaves in its crosses, as well as after self- 
fertilization, exactly after the manner of O. scintillans and O. lata. 
From this fact and from the cross Lamarckiana X pallescens, pre- 
viously mentioned, it seems probable that the other new dimorphic 
mutants, namely O. pallescens, O. liquida, and O. Lactuca, will 
follow the same rule if tried in the same way. This rule is evi- 
dently independent of the external types of their characters, but 
must depend upon internal properties of their hereditary qualities.“ 
I will now give briefly the necessary details concerning the 
crosses mentioned in tables IX and X. As already mentioned, 
all these crosses were made in 1913 with plants of the same origin. 
For every cross a single specimen was chosen and some flowers on 
the lower part of its main spike were castrated. The seeds were 
sown in February 1914, the seedlings transplanted into boxes, and 
from these, as a rule, about 25 specimens of each culture were 
placed in a bed in April and May, giving them a good soil and 
light exposure and plenty of space to insure a vigorous develop- 
ment until the time of flowering and of fruiting. 
O. canaXO. biennis Chicago—A group of 71 specimens, all 
of which produced high stems and 25 of which have flowered. 
One was a mutant, combining the gray narrow leaves of O. cana 
with the marks of the stature, foliage, and flowers of O. Jala. 
The plants of the type of O. cana were exactly like pure O. cana 
at the beginning of the flowering period, in July, when they had 
reached a height of 70 cm. The remaining plants were like (O- 
Lamarckiana XO. biennis Chicago) laeta and velutina. The recipro- 
cal cross yielded 59 specimens, of which 5 remained in the condition 
4 On these questions see Gruppenweise Artbildung, pp. 268-295. 1913- 
