256 
4. The wheat sown September 29 and October 6, 1880, which 
headed out December 30 and February 19, was injured as to the heads 
by the subsequent frost. 
5. The seeds sown October 20, 27, and November 3, 1880, flowered 
between the 4th and 8th of June, 1881, but at this time there was 
experienced at Paris a spell of very cold weather, the minimum daily 
temperature being 3.1° C., and even white frosts were reported, so 
that wheat which was then in flower was badly injured. 
6. In general, the dates November 10, 1880, to December 15, 1880, 
are those indicated as most favorable for sowing wheat in that year, 
and the crop of 1881 may be predicted as likely to be small, but of 
excellent quality. 
The grape and wine crop.—tn a short study on the relation between 
the vine and the weather, Marié-Davy (1882, p. 290) states that, in 
general, the annuals, such as the cereals, concentrate all their energy 
in the formation of the ear and the seed or grain. Their work is then 
finished and they die. The next year’s crop of these annuals is 
largely under the control of the husbandman, who can obtain seed 
from more favored regions if his own crop was inferior. 
On the other hand, the work of the vine, like all perennials, is not 
merely to ripen its fruit and seed, but to preserve its own individual 
self for usefulness in future years. Therefore it elaborates out of its 
own sap not merely leaves and fruit and seed, but a store of woody 
fiber. Corresponding to this more complex system of growth the 
relations of the perennials to the chmate are apparently more complex 
than the relations of the annuals, and, it may also be added, the range 
of geographical distribution, whether by nature or by cultivation, 1s 
more restricted. 
Our studies will be confined to the data furnished by the observa- 
tions at Epernay (1873-1881), to which Marié-Davy adds other data 
computed from the observations made at Montsouris, in which latter 
computation certain laws of growth of the vine as established by 
Gasparin were adopted. 
In the neighborhood of Paris the leaf buds of the vine burst open 
in May when the mean daily temperature has permanently passed 
above 11° or 12° C. Assuming that the mean of twenty days, as 
observed at Montsouris, will give this date (which was unfortunately 
not observed at Epernay), we obtain the figures in the first three col- 
umns of the following table. In some of these years the early leaf 
buds were undoubtedly killed by nocturnal frosts, but they were soon 
replaced by other buds, and the dates here given must be adopted in 
the absence of actual observations, especially when we remember that 
the quantity and quality of the final crop of grapes depend not only 
