LIFE HISTORY OF TIMOTHY 41 
tion ranged from 60° to 72 z F. Large numbers of timothy florets 
bloomed on each day during this period, except on the morning of 
June 29. when practically none bloomed; the minimum tempera- 
ture during the preceding 24 hours had been 71° F., but the sky 
was cloudy, and there was a heavy rainfall in the afternoon of June 
28. In most seasons there are more frequent interruptions in the 
blooming process on different days during the period when timothy 
meadows are at the height of bloom than there were from June 
20 to July 3. 1921. _ 
The color of a timothy meadow in bloom varies greatly at dif- 
ferent times during the blooming period. These changes are chiefly 
due to changes in the color of the anther sacs at different times and 
to variations in the number of florets that bloom on different days. 
PROLIFERATION IX TIMOTHY 
Proliferation has been observed to manifest itself in the inflo- 
rescence of timothy in the ways described below : 
Proliferating florets, each having one bract enlarged to resemble a leaf. 
Either the pistil or stamens, or both, are usually present. 
Proliferous shoots, capable of developing directly into plants. In a pro- 
liferation of this type there are several leaflike parts, but no pistil or 
stamens. 
Spikelets with elongated rachilla. 
In addition to these three forms of proliferation, branches have 
occasionally been observed on the same heads bearing proliferating 
florets. 
Proliferation in grasses is not peculiar to timothy. Goebel (12, 
vol. 1, p. 178-185) states that it may occur in Poa alpina and P. 
bullosa. Hackel (13. p. 31-32) has observed this phenomenon in 
P. striata, Deschampsia alpina. and Festuca fuegiana. Jenkin (22, 
p. Jj.18-Jj.19) shows that the tendency to proliferation is especially 
marked in certain strains of F. ovina; he has also observed prolifer- 
ation in F. rubra, Cynosums cristatus, Alopeeurus pratensis, and 
Lolium perenne. Other species could be added to these lists. 
CONDITIONS UNDER WHICH PROLIFERATION OF TIMOTHY OCCURS 
Ward states that proliferation occurs in " some grasses growing 
in high latitudes, or in mountainous regions, or in moist situations " 
(37, p. 133-1 3 '4). Proliferation in timothy has been observed in 
northern Ohio almost exclusively on heads which develop during 
the fall months, and especially on those which appear during the 
last, few weeks before growth is checked by cold weather. That 
proliferation does less commonly occur in timothy earlier than the 
fall months is indicated by occasional botanical specimens with 
proliferating florets which have been collected in other localities. 
In the Gray Herbarium at Harvard University there are two speci- 
mens of PMeum prate rise, both with proliferating florets, collected 
during the summer months. One of them was collected by J. C. 
Parlin on the banks of the Androscoggin Eiver. in Maine, August 
16, 1906 : the other was collected bv Sereno Watson in Rubv Valley, 
Xev., at an altitude of 6.000 feet! in July. 1S62. In the National 
Herbarium at the Smithsonian Institution, Washington, D. C, there 
