INDIVIDUAL SPECIES. 35 
Here again probably we see the effect of the other consti- 
tuents of the seeds-mixtures, as the seeds of this plant were 
included in equal quantities for the two areas, 
Trifolium repens. 
On an oat stubble following ley, the present writer has found 
a Sp. fr. of 18 for this plant,? but it is not included in a list of 
arable land weeds given by Stapledon (17). Brenchley (3) 
obtained 131 seedlingsof this plant from the soil from four holes 
(6in. x 6in. x gin) in a field which had been under grass for some 
years. 
The present writer collected ripe seed in 1916, and in April, 
1917, a portion of these were treated with fine emery paper. 
These, and others which had not been treated, were then placed 
under similar germinating conditions, and the following germina- 
tion results were obtained :— 
1o days. 25 days. 2 mths, 4 mths. 6 mths. 8 mths, 
Treated: i... (66? was GP ase OF ace BG. 86 sce 863 
Untreated.e; J asx Fo as FF «ee TO ws WO ace 72 
At the end of eight months the test on the treated seeds was 
discontinued, and the untreated seeds were allowed to dry 
gradually, and to remain in the dry condition for four months. 
At the end of this time there were 81 per cent. hard+ seeds left, 
while 7 per cent. had become mouldy. 
The hard seeds were then collected and treated with emery 
paper, but in this process a further 7 per cent. of the original 
number were lost, leaving 74 per cent. for further testing, 
In three days, 48 per cent. of the original number had 
germinated normally, and 5 per cent. abnormally.s The test was 
lAnglesey, poor soil at 150 feet. 
2 Numbers in percentages of total seeds tested, 
8 Some seeds had probably escaped treatment. 
*7.e, seeds which appear normal and healthy although they have not 
germinated under conditions which produce rapid germination of other 
apparently similar seeds. 
5This was probably due to the emery paper treatment, 
