238 
Journal of Agricultural Research voi. xxvii, no. 5 
Percival ( 10 , p. 122-129) states that the lowest flower of a spikelet 
blooms first, with the others following on successive days. Friiwirth (2) 
notes the exception that the second flower, instead of blooming on the 
next succeeding day, may sometimes bloom in the afternoon of the first 
day, while the remaining flowers may bloom on the following day or on 
the second day after the blooming of the second flower. 
More than half of the first or lowest flowers in all the spikelets on the 
seven heads under observation were observed to bloom before the second 
flower in any spikelet bloomed (Table VI), and about 85 per cent of the 
first flowers bloomed before any flower in the third position bloomed. 
Nearly two-thirds of the second flowers in turn bloomed before the third 
flower in any spikelet bloomed, and a similar relationship exists in the 
blooming time of the third and fourth flowers. If the earliest blooming 
of second, third, and fourth flowers in any spikelet on a head is considered 
as marking off periods of blooming for that head, it is found that a part 
of the first or lowest flowers bloom subsequently to the opening of the 
earliest of the third flowers and even the earliest of the fourth flowers. 
Similarly, some of the second and third flowers will bloom after the first 
blooming of third and fourth flowers, respectively. The data on these 
periods in the heads under observation are shown in Table VI. 
Table VI.— Relative period of blooming of the first to fourth flowers in the spikelets of 
seven wheat heads 
Percentage of flowers in each position blooming in 
each period. 
Relative period of blooming. 
Previous to the first blooming of a second 
flower. 
From the blooming of the earliest second 
flower to the blooming of the earliest 
third flower. 
From the blooming of the earliest third 
flower to the blooming of the earliest 
fourth flower. 
Subsequent to the blooming of the earli¬ 
est fourth flower. 
1st. 
2d. 
3 d. 
4th. 
All. 
Per cent. 
54 - 13 
Per cent . 
Per cent. 
Per cent. 
Per cent* 
17 - 74 
64. 40 
“1.79 
30-83 
29. 06 
69. 70 
10. 53 
27. 97 
38.57 
4.51 
7-63 
30 . 3 ° 
98. 21 
24.63 
100. 00 
IOO. OO 
IOO. OO 
IOO. OO 
IOO. OQ 
« One flower only; disregarded in period determinations. 
The numbers of flowers that bloomed at the different hours of the day 
and night throughout the entire blooming periods of the seven wheat 
heads are shown in Table VII. Since the actual time of blooming of 
flowers was not observed between to p. m. and 1.55 a. m., all of the 
flowers blooming between these hours are grouped and recorded as of 
this period. The maximum number of flowers blooming on a single 
head in one day was 25. This occurred on May 16, one of the most 
active blooming days in the period of observation. Obermayer (9) 
observed a maximum of 23 flowers on one head opening in one day. 
The maximum number of flowers blooming on a single head in one 
hour in this study was found to be eight, these being divided equally 
between the two sides of the head. The blooming on all heads was 
completed within 101 to 123 hours. 
