240 
Temperature sums from January 1 to the date of first blossom (by Hoffmann’s 
method) at Giessen and at Frankfort. 
[Z. O. G. M., Vol. X, 1875, p. 251, and Vol. XVI, p. 331. All in Réaumur degrees. ] 
Giessen. 
Plant 1866-1869,| 1875, nae forts 1845, 
eels ner _| Ther- Ther- 1 URE ae 
mre Stek pee: mometermometer| — B,. 
1. | 2 
Moniceratalpi genase. s22- as eaea ae eee eee eee i Bakeyy O16 boas [oot fees Ee 
Sambucus migra. = Scns e Sect omen a ee eee 1,678 GES 9 a iy ee ee a eee 
IBeErvoristVUleatis seees eee eee ete ae eee 1,377 TOON | 2225 Sue S28) '- ee Se 1,110 
IPrunusiaVvillM ne. oa seess eee! eee eee eee 1,077 S20" 0 222 352. ee oe eee 800 
Svan oa tyUl Cad S een eee eee ee 1,393 VS OOVs\ 22. oes ee | ee 
Aesculusihippocastantum\: 222-2. escss=s=-se nee 1,317 L069 | 22:2 5 = Sane See eee 1,065 
Va bIS: VANITOLS 82450 a So ose tae hee 2d SEE She EES 2,600 1,995 2,697 2603)\ tae et 
IPTrUNnUS'SPIN OSA pease esa ese eee ee eee eee eee aes 81942 Shee ee ae ee 822 
Temperature sums (by Hoffmann’s method) at Giessen from January 1 to first 
blossom, for plants that blossom in midsummer and autwmn. 
[Z. ©. G. M., Vol. XVI, p. 331, and Vol: XVI p. 1305) M. 25 Vol. I, ps 40%, and Vol sii, 
p. 546.] 
Ther- | Thermom- 
Thermometer By. 
mom- eter By. 
Plant (always same stock). eter A, | 
1866- | 1880. | 1881. | 1880. | 1881. | 1882. | 1883. | 1884. | 1885. | 1886. 
Aesculus macrostachya ___| 3,853 | 3,504 | 3,479 | 3,191 | 3,254 | 3,929 | 3,846 | 3,639 | 3,546 | 3,556 
Aster amellusi seco) 5 225 ole 8,980: | 45.091 | 4,003) | 3,753 | 3,768 | 4,522) 4,569) 4,363) |- 2222S )e 2 Secae 
Lilium candidum -____.-_-- 2,710 | 2,872 | 2,855 | 2,603 | 2,639 | 3,112 | 3,228 | 3,010 |.-...._].------ 
Linosyris vulgaris --------- 4,083 | 4,091 | 4,260 | 3,753 | 4,040 | 4,555 | 4,670 | 4,502 |_.---.-|------- 
Plumbago europaea ------- DESL Sed, 40D u kas 2ol sas Ook Oli eee ye eee ae) eee 5,386 | 5,494 
Pulicaria dysenterica----_- BSyS81F 23; GIS xs 2Goul tal OO alo O40 lee eee | emer ae |e ee | eee 
The contrast between the ordinary spring of 1881 and the very 
early spring of 1882 with its preceding warm winter, affords a test of 
the question as to how much the thermal constant is lable to change 
with the variations in the seasons. Hoffmann finds that although the 
first blossoms in the spring of 1882 occurred fifteen days earlier than 
usual, yet the sums of the maximum temperatures since January 1 
were not much changed. The figures as given by him (Z. O. G. M., 
Vol. XVII, p. 460) are reproduced as follows: 
Thermal sums. Date Recee to 
Plant. i 
1881. 1882. 1881. 1882. 
Canpinus betulus2<* 22: 22 2 Se eee 1,159.7 | 1,184.6 | Apr. 19} Apr: 2 
NAnixXcOUlr OPACH.-2225 aa-k eens eee ee ee eee 789.9 759.9 | Mar. 30 | Mar. 15 
moniceraalpivena- 222. -6- fae se- ae eee a oe eens 1,471.7 | 1,490.4 | May 6) Apr. 19 
IPrunUS SpINOSa. 2 <5. So Lee eoels = eee a eee eee ae | 1,159.7 | 1,091.6 | Apr. 19 | Mar. 31 
Ribes svOssullariat se se. 2s ke eee See eae eee eae ee 1,086.5 | 1,091.6 | Apr. 16) Mar. 31 
@ratacrusioxyacantha..- 22225)! ae eee oes 1,681.6 | 1,782.5 | May 15 | Apr. 30 
Sarothammussvll paris: «2- <= see: oe ee ee eee 1,790.8 | 1,751.9 | May 20°} May 1 
Berberisvallearis’: 225 3! esa Poe eeens eee eee eae 1,681.6 | 1,751.9 | May 15 | May 1 
wks 
