at different Degrees of Constant Temperature. 251 
22°15; the next morning at 10 o’clock it was 21°2, and on the 
following day at 10 it was 19°°9. 21°1 may be considered the 
approximative mean. ‘The following are the results :— 
Lepidium. Germinated in thirty-eight hours. 
Linseed. Germinated in about thirty-six hours. 
Maize. Two seeds germinated on the forty-second hour, and 
others followed. 
Nigella. In four days and a quarter. 
Sesamum. Germinated in from thirty to thirty-six hours, 
without my being able to determine accurately, in the middle of 
the second night. 
Sinapis. One seed germinated in eighteen hours, and the others 
followed ; say, twenty-two hours for the first of them. 
Trifolium. Some seeds germinated in forty-two hours. 
On the 5th of August the temperature had fallen, and the 
mean of the 2nd of August, from 5 in the afternoon till 10 in the 
morning, may be estimated at 20°°4. Jberis germinated under 
these conditions in two days and three-quarters. 
Collomia did not sprout. Its seeds were kept and watered at 
temperatures of from 18°°8 to 20°'4 (mean from the beginning 
19°6), and on the 18th of August (fifteen days and a half after 
the sowing) one germinated. 
To be sparing of the melon-seeds, of which very few were left, 
I did not then sow them, but began again on the 16th of August; 
and at a mean of 19°-4, having varied from 18°°8 to 20°:4, two 
seeds out of ten germinated in two days and twenty hours. 
At a temperature of from 24° to 25°. 
On the 19th of July, a sowing was made in a room the tem- 
perature of which was about 26°, and subsequently, from the 22nd 
to the end of the month, 23° to 24°. The seeds were placed upon 
the sand in a drawer which shut tightly, and to guard still more 
against external variations, they were covered with sheets of brown 
paper. The sand was watered, and the paper moistened. The 
temperature in the sand remained for three days between 24°-9 
and 25°-2 (mean 25°05). Under these conditions, 
Linseed germinated in thirty-eight hours. 
Maize. One seed out of twelve germinated in twenty-three 
iat ; but half the seeds had not germinated until after forty-four 
ours. 
Melon. Two seeds out of ten germinated in forty-four hours, the 
others followed. 
Sesamum germinated in from twenty-one to twenty-two hours 
and a half. This extreme rapidity having prevented me from 
