Sept, i, i93i 
Rate of Culm Formation in Bromus inermis 
809 
The areas of the 97 plants were computed from their diameters at 
the last counting date. At that time each plant occupied on an average 
284.25 square cm. On the same basis the theoretical plants, after a 
year’s steady growth, would cover an area of 5,244.241 square cm. 
Stated in diameters, the measurements would be 19.02 and 81.71 cm. 
in diameter, respectively, for the last counting date in 1916 and after 
the lapse of one year. The use of equation I would have increased 
the diameter of the theoretical plant only about 5 cm. It is worth 
noting that the plants discussed in this article were not far removed 
from the calculated size shortly after the beginning of the growing 
season in 1918. At that time the plants were still deficient about 1 
dcm. or more in diameter from the theoretically estimated size. Assum¬ 
ing five months each season for rather rapid culm formation, it is evident 
that the given equations did not assume too much, provided culm for¬ 
mation proceeds the third season as rapidly as during the first and 
second seasons. 
The foregoing does not imply, of course, that the number of culms 
during the third season was the number deducible from the equation. 
A plant may have a certain area at the close of the growing season. 
Such area will receive constant area increments during the next growing 
season. The original area also will be replenished with culms, but there 
is no precise knowledge at all as to the comparative number of culms 
for the two consecutive seasons upon the original area. Again, with 
certain plants, after the first season, deterioration begins within the 
original area, and such area of deterioration gradually enlarges. Within 
such an area the number of culms would be very evidently less than 
before deterioration began. 
ANALYSIS OF CULM FORMATION 
An examination of the data secured indicates that a closer analysis is 
possible than is given above. At the first count, as previously indicated, 
the plants fell into five groups in regard to number of culms. As but 
two plants had five culms, this group will be disregarded in the present 
analysis. There are thus left four groups constituted as follows: 
CULMS PER PLANT. 
1 . 
2 . 
3 . 
4 . 
NUMBER OF PLANTS. 
. 28 
. 24 
. 28 
. 15 
Total 
95 
The mean was secured for each group for each counting date. The 
means of the four series are shown in Table II. 
