Plantayo Lanceolata Ranwsa. 149 
be only partial. In spite of the most careful selection 
and isolation during the time of flowering this race every 
year produces plants not one of whose spikes, even when 
there are a hundred to the plant, exhibits the smallest 
trace of branching. They are obviously to be regarded 
as atavists. 
The proportion in which these atavists occur seems 
to be fairly constant, fluctuating however from year to 
year. It can be slightly increased or diminished by the 
choice of favorable or unfavorable seed-parents; but it 
does not seem possible to effect an essential and per- 
manent improvement by continued selection, at least not 
to a degree that would open a chance of altogether elim- 
inating the atavism. 
In the first years of my cultures I did not pay partic- 
ular attention to this phenomenon ;" moreover my experi- 
ments were on too small a scale to afford numerical data 
of any value. But I found atavists as well as ramosa- 
plants every year, although I always collected my seeds 
from the former. I did not determine the proportion 
until the fifth generation (1892) was reached. I should 
state that I have isolated my seed-parents every year, 
cutting off as many as possible of their unbranched ears 
before they flowered. Pollination which had to be left 
to the wind was therefore confined to the group of se- 
lected seed-parents, whose number scarcely ever ex- 
ceeded 10. It was as pure as it was possible to have it. 
I obtained the following figures : 
GENERATION PERCENTAGE OF ATAVISTS 
5. 1892 46% 
6. 1894 50 %, 58%, 59% 
7. 1897 47% 
8. 1898 45%, 56%, 59% 
8. 1900 52% 
