264 
: ae & : 2 ; 
meteorological conditions must be accessible, samples of which I have 
prepared for twenty United States stations.“ 
If we suppose some wheat to have been sown on the 22d of Septem- 
ber, 1871, near Paris, and if we adopt the rule established by Gas- 
parin that the vitality of the seed is actively aroused as soon as its 
temperature in a moist earth exceeds 5° C., and that it germinates 
visibly when it has received a sum total of mean daily temperatures 
that is equal to 85° C., and that the sprout rises above the surface of 
the earth in a few days after the seventh, then we obtain six days as 
given in the following table for the interval from sowing to germina- 
tion. A similar computation for every other date of sowing, as given 
in the following table, shows at a glance the effect of the temperature 
of the soil on this phase of plant life. 
Duration, in days, from sowing to germination of winter wheat at Montsouris, 
France, for the years 1872-1881. 
| ' Germination. 
| | | Av- | 
| | | erage 
| |e ae | ; dura- 
Date of sowing. | 1871. | 1872. | 1873. | 1874. | 1875, | 1876. | 1877. | 1878. | 1879. | 1880. | 1881. | tion | Aver- 
| | for age 
the | date. 
years 
| | 1872- | 
| 1881. | 
= ee Senta E Nes 
September 22__- 6 7 it 5 5 7 Samad gy G 6 7 | Sept. 29 
September 29 __- HOA 10 ee Oval saener 6 6 8 | 7 (Nes Mea 10 7 | Oct. 6 
October 622.022]. 18) 8.) Wl AN AOE et eBets pS HA PSN Ne aT ae Aleaneon Ocrammts 
October 13 ___... 81) 78.9) v6.) 8 rl On ol OO le ee Su@e med 
October 20 ------ 12 8 13 TKO) Ap UY alt 7 ) 22 15 11 | Oct. 31 
October 27 -_--.- 70 8 13 g) il 16 8 29; 14 18 13} 20]! Nov. 16 
November 3....| 72] 15] 15] 14] 8| 12] 8| 2| 16] 14| 7] 20| Nov.23 
November 10.... 77 | 15) 17) 32 8 8) 14) 48)) 98\| 695) 105) 33)) Decras 
November17_..| 70| 9] 12} 49] 41] 18] 12] 44] 93] 21] 10] ‘86| Dee. 28 
November 24 .._| 638 10 | 25 53 42 11 25 39 | 89) 17 26| “37 | Dee: 31 
December 1----- | 56 16| 43) 48 35} 8 46 69] 82} 12 42} 42) Jan. 12 
December 8. -.-- | 49 16) 36 42 28 | 22 67 62 75 | 11 67 41 | Jan. 18 
December 15.---| 42] 12] 25 35 Bail 12 60 55 | 68 13 60 35 | Jan. 19 
December 22..._| 35 11 | 30 28 56 14 55 48 61 | 43 57 38 | Jan. 29 
December 20....| 28 LOMie= 26 21 53 9 49 42 53 | 44 50 | 34] Feb. 1 
| | | | 
In studying the preceding table we recall that the duration of 
germination varies shghtly with the condition of the soil and the 
depth of the grain below the surface; these two considerations will 
be perfectly allowed for if we observe directly the temperature of 
soil by a buried thermometer. Such observations are earnestly recom- 
mended to all agricultural experiment stations, as they are, evidently, 
more directly applicable to the growth of plants than any crude 
@'These tables are omitted in the present edition. 
