224 MR. I. H. BURKILL ON SOME VARIATIONS IN 
flower, or 80 per cent. On the last occasion of my examining 
the plants on the cinder-beds (Aug. 7th), when those of C were 
showing that they certainly could not exist any longer, I took 
advantage of a young growth (I), 4 inches high, side by side with 
the old plants, to make a comparison, which gave the following 
result :— 
Tase III. 
Effect of Age on Number of Stamens developed in the Flowers of 
Stellaria media. 
No. of No. of No. of Percentage 
flowers, | stamens. |staminodes, | 9. stamens 
present. 
Very old plants......... 49 159 3 39:45 
Very young plants wee 49 184 3 37:55 
And so, as the 9 organs do not change with age, the plant 
appears to become less d (less $ by reduction of d ) as it grows 
older. 
Effect of Temperature.— Warmth, as Miiller* thought pos- 
sible, appears to have an effect in increasing the number of 
stamens ; this is shown in Table I.: E and F were grown in the 
warmest place; and in them the flowers with three stamens 
(26:70 per cent.) were less numerous than those with four or five 
stamens (28°41 and 30:40 per cent. respectively): of the other 
columns, C was from a warmer place than the rest; and here 
the percentage of four- and five-stamened flowers is larger than 
in any other case, except that of E and F just quoted. In 
Table IV. the variation from week to week is given. From data 
kindly supplied to me by Mr. H. F. Newall I have endeavoured 
to find causes for the marked irregularity seen in it, but with no 
great success. The one marked Cold period (Feb. 18 to 24) may 
have had some effect, but otherwise, wet or dry, hot or cold 
weather seems to have passed without any definite influence. 
* ‘ Fertilization of Flowers,’ p. 135. 
