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wine this year should have had a great similarity with 1874. Never- 
thelss, the wine of 1878 was not of very good quality, which can 
perhaps be attributed to a too prolonged growth of the vine stems, 
caused by the humidity of the soil. If in general a good wheat year 
corresponds with a good wine year this rule is far from invariable. 
In regard to quality the vintage depends but too often on the late 
spring frosts. 
The extremely important part played by light in agriculture makes 
us regret that the actinometer should still be so little known. It 
perfectly replaces the thermometer for agricultural purposes, but the 
thermometer can not take its place. 
In his Annuaire for 1882 Marié-Davy gives the following study of 
the development of cereals, wine, and other crops: 
Cereals.—The cereals offer a great number of varieties, and this 
number increases annually, but often the differences that we see be- 
{tween them are due to certain influences of the soil and climate 
which disappear by change of locality. However, there are some 
varieties whose qualities have been fixed by long-continued cultiva- 
tion in the ordinary way or by long-continued selection, and which 
present decided advantages for the specific climates. 
The varieties brought from the south are more sensitive to cold 
than those from the north, and can not be propagated without special 
precautions in higher latitudes or at greater altitudes than belong 
to the localities where these varieties were gradually developed. The 
varieties brought from the north are generally more precocious and 
suffer more from dryness. The expressions “ early ” or “ late” have 
reference to their behavior in the new locality. The grain brought 
from the south comes to maturity at a later date than that raised in 
the north. 
Influence of heat and light on development of wheat—We shall 
divide the development of wheat into four phases, whose dividing 
epochs are the processes of (1) sowing and germination, (2) heading 
out, (8) flowering, and (4) ripening. According to Gasparin the ger- 
mination of wheat begins when together with the necessary moisture 
it also enjoys a temperature in excess of 5° C., and it sprouts when it 
has received a sum total of effective mean daily temperatures (above 
5° C.) equal to 84° C. Its sprouts shoot above the soil a few days 
later. Some wheat sown by Marié-Davy April 23, 1880, was up on 
the 4th of May, the sum of the mean temperatures being 96°, so that 
the germinating sprout had taken about two days to grow from the 
seed to the surface. In the following table columns 2, 3, 4, and 5 
show the duration in days of the period required for the germination 
of wheat supposed to be sown at Montsouris in the different years on 
four different dates—a, b, c, d—as stated at the heads of the columns. 
These durations are calculated to the nearest whole days, on the 
