360 Gates. 
all the plants lose most of their red color, so that it is impossible to 
distinguish the two forms by any character. Later, from the time 
the buds develop until blooming has ceased, they can be distinguished 
at a glance and there is never the slightest uncertainty as to where 
an individual belongs. I mention this fact because it might be 
expected that there would be at least occasional intermediates, but 
this particular variation is absolutely discontinuous. The range of 
pigment variation in the O. rubricalyx buds was extremely small, as 
already mentioned. The plants which developed O. rubricalyx buds 
were always the same individuals which had earlier in the season 
exhibited an excess of red in their rosettes. 
Thus it is seen that O. rubricalyx fluctuates about a new mode, 
and that nearly every part of the plant shows an increased capacity 
for anthocyan production. This is true even of the stems. In 
O. Lamarckiana as well as in O. rubrinervis and the other mutants, 
the long hairs on the stem arise each from a papilla whose cells are 
always anthocyanic. In O. rubricalyx there are in addition red patches 
on the stem at the base of the papillae and (particularly near the 
top of the stem), these frequently extend so as to fuse with each 
other, forming red areas of considerable size. In figs. 4 and 5 
are reproduced photographs of the mature flowering shoots of 
O. rubrinervis and O. rubricalyx. They differ in no respect except in 
pigmentation. 
IV. Crosses with ©. rubricaly& and ©. rubrinervis. 
In 1909 a series of crosses was made with O. rubricalyx, with the 
intention of testing completely its hereditary behavior as compared 
with that of O. rubrinervis and other mutants. Many of the seeds 
were planted in 1910 but unfortunately the transplanting was delayed 
too late, so that most of the plants remained rosettes. During my 
absence in the earlier part of the season they passed the stage of 
the rosettes in which O. rubrinervis and O. rubricalyx are distinguish- 
able, so that those which failed to bloom remained undetermined on 
this point. Certain points which would have been settled must there- 
fore remain uncertain, but in the main the hereditary behavior can 
be described and compared with O. rubrinervis. The behavior of the 
reverts from O. rubricalyx to O. rubrinervis was also tested and was 
found to be the same as O. rubrinervis of pure pedigree, i. e. they 
behaved like Mendelian extracted recessives. 
