289 
The probable errors of these sums, considered individually, are 
quite large, and their agreement from year to year is not sufficient 
to justify the belief that we have attained to a satisfactory expression 
for the connection between the temperature and the date of flowering. 
Flowering of rye and winter wheat—Harvest of rye, winter wheat, 
and spring barley.—A new investigation, based on an increased number 
of stations for the years 1886 and 1887, gives for the rate of retarda- 
tion of these epochs the following figures: Flowering of rye, 4.2 days 
per 100 meters; flowering of winter wheat, 4; harvest of rye, 4.5; 
harvest of winter wheat, 4.3; harvest of spring barley, 4.2. We can, 
therefore, as before, take 4 days as an approximate value for all these 
phenomena. 
The mean temperature at the time of flowering is determined, both 
for daily means and for daily maxima, as follows: 
Daily mean. ‘Daily maxima. 
Flowering of plant. 
1886. | 1887. | 1886. | 1887. 
oh Ge OO on Gk NG: 
EUV OMe ee oe Ee econ hoes ewe J 4o 5 Hee cea sasaiuac ges ceaes ese e522 15.4 12.3 22.1 18.3 
\AVO@ Rb oe ee ea NAR el So RR ee a 16.2 17.3 22.0 24.3 
Again, the average numbers agree well from year to year, but the 
individuals from which they are derived have a wide range. 
The sums of the mean daily temperatures, less 5° C., counting from 
December 1 for the winter rye and wheat, but from March 21, for the 
spring barley, are as follows: 
Sums of temperature. 
| ae Aver- 
Plant and stage. | 1886. | 1887. age. 
lec | oa | ce 
EOMOTSEE SOREN O Mos at peas Rutt ha ket be ed Be MANADO A Le Sa ae ake 313 415 364 
Hiowenrine of winter wheats 25-25 64) 9s =e Se ere see eee 735 630 2 
FERRE OSLO Lets yi Clee eee tae en ee oa See Ae ae eye et ee te ee ES | 1,080] 1,017 1,048 
EA EVeS TO LaWall COnnwilea ti cee mee se neers Sense eee ee ee ee | 1,286 | 1,185 1, 236 
Harty oso OMSprin ps DaliC yess =. een nce tee ees ee UE eee | 1,214 | 1,120) 1,167 
From the flowering to the harvest, on the average of these two 
years, rye has received 1,048—364—684° C., and winter wheat 1,236— 
682—554° C., but on the average of eight years, 1880-1887, the sums 
of temepratures, less 5° C., have been, for rye, from December 1 to 
the flowering, 477° C., and from flowering to harvest, 607° C.; for 
winter wheat the numbers are, respectively, 708° to 549° C. From 
the beginning of vegetation up to harvest the numbers are: For rye, 
1,084° C.; winter wheat, 1,256° C.; spring barley, 1,103° C. These 
results can be considered as having definitely established the fact that 
2667—05 m——19 
