173 
(3) RIPENING. 
During increasing heat: °¢, 
Ser inbeo ty cheselimnstree perenes = its © Sk pe ws ok ee ee ee ee 1250 
(GRAM Teer Se ak eS ee ee ee ee ee 14. 2 
Binsta Cherries a DLO AG MUCH IN See ee ee Le ae oe ee ee 16. 0 
IESG OWN SRO feSaln Old =" ==. = Sp ae ee 2 eee 17. 0 
Currants] raspberries + Sstrawherries: eherrieso"/ Ja ee 17.8 
Morella cherry tree; apricot; plum tree; barley ; oats________________ 18. 0 
InAyeNe 5 te eS SL hey eee 8 ee Es yar eee ie phe ye See 19. 0 
Reachwerec wnarvest Ol CORN 4222 te te Ao a A 20. 0 
HiEsigiesroTeene cage spiMms= 2 2 ee 200 
First grapes, called madeleine; melons in free earth_______________-__ 2285 
FSCS TPT [0 ee Same cee RS ee RD ede ee ee Bee 22.6 
During decreasing heat (for fruits which have received a sufficient quan- 
tity of increasing heat) : 
THORS C=C HES tan Uits eee ee eee Se ee Fe ee a ee ee ee ae 18. 2 
TCU COMET) O LATO CS a ee ee ee es ie ee ee Se Wee) 
Mois amide CheStiltS:. =e, en eS ee ae 16. 2 
LE XG Sm SKe RTO EH SS i a a I ca eh 1525/0 
Sel filets Tae eset ee ree er een, Md EY IA RASA oe ER oS PERN EB a 13. 0 
COTS VS eee ey de ee NR ed Se Sr sees SEE pS Tete rg rd Vel eheles eh 10.0 
Note.—It can be easily understood that the fruits which require the greatest 
prolongation of heat ripen last and are gathered at periods of the lowest 
temperatures. 
Lachmann, in his Entwickelung der Vegetation, counts the sum 
total of all the temperatttres at his station (Braunschweig, Germany ) 
from February 21 onward. 
Linsser, for north temperate countries, counts from the date when 
the temperature 0° C. is attained, but for warmer countries he counts 
from the date when the lowest temperature of the year is attained; 
which date would, according to his calculations, be the 8th of Febru- 
ary at Braunschweig instead of the 21st of February; but, according 
to the normal values resulting from the thirty years of observation 
by Lachmann, this change would only make his sum totals about 
10° C. larger. 
Tomaschek, as quoted by Fritsch (1866, L. XIII, p. 297), takes the 
mean of all positive temperatures as observed at 6 a. m., 2 p. m., and 
10 p. m., omitting the individual negative observations instead of the 
negative daily averages. He counts the sums from January 1; this 
method gives figures that agree very closely, at least in Hurope, with 
those given by Fritsch’s method. 
Kabsch, as quoted by Fritsch, attempted an improvement on the 
method of Boussingault. His formula is especially appropriate to 
the annuals, but not to the perennial plants. His method of comput- 
ing the thermal constant is expressed by Fritsch in the following 
formula: 
math( Fs on 
WY; 
