288 
and 3.5 for the oak. For all these he adopts 4 days, as in previous 
vears. 
Leafing—The mean temperatures at the dates of leafing for 1886 
and 1887 are given, as follows: ' 
Data for 1886 and 1887. 
Mean of Mean of 
Mean of |daily max- Mean of |daily max- 
Plant. daily tem-| imum Plant. daily tem-| imum 
perature. | tempera- perature. | tempera- 
ture. ture. 
° CG: ° C: . ° GC: ° (OL 
Telacee eae en Sele ey 9.4 14: Sh|| Birch ees. e ete | 9.9 15.3 
Chestnuts 6-2 10.6 16:23|| {Opto eees eee eee Ly, 17.6 
The sums of temperatures received by these plants from the last 
freezing period up to the time of leafing, and counting from 0° C. as 
the initial temperature, are as follows: 
Sums of daily Sums of daily 
means. maxima. 
Plant. ee ee 
1886. 1887. 1886. 1887. 
On OF (OR Of, CHIEF 
TAGES ese i ee ey ea ee Cee ee See ee ee . 3856 402 622 772 
Westboro See oe 469 531 788 983 
TBST RO) 0g es EE SE ge Te PS ESD Es ee SEE 465 531 796 981 
Oakes 2xieee See Seles ee eas Be tee, 2s 8 Clo ey nee 622 682 1,016 1,208 
The flowering of the lilac, chestnut, elder, and linden.—A new 
determination of the rate of retardation of flowering for these plants 
gives 4.7, 4.2, 4.4, and 3.8 days per 100 meters, respectively, for 
which, as before, 4 days is adopted. The mean temperatures at the 
times of flowering for the years 1886 and 1887 are as follows: 
Plant Day | Dey 
MOL |) Oe 
WH AC2 Fae doses echo sees akesd Gesss Sele ae See sme neni tee Re ee cee oo eee eee 12.2 17.8 
Chestnuts. ho. ee sass Sa Fe Be ee ee ee eee ere ee ne 12.8 18.7 
DG Vc) hes Rael an oe epg er nea ee Meo ek Pee a a LR eh Se 15.2 21.0 
ini enters: Salute sc ee ee 8 ae cere ee (alee estes Se ce Nhe oie eee 22.5 
16.4 
The sums of temperatures above 6° C., counting from the last freez- 
ing period and up to the date of flowering, for the years 1886 and 
1887 are as follows: 
Sums of daily | Sums of daily 
Pikae means. TEES 
1886. | 1887. | 1886. | 1887. 
(Gf one: a Of Op 
Diilae ce eee es Se a ee ee ee ee eee 621 661 | 1,020 1, 184 
Chestnut, oo fechat ese tk & lo heh atin DUE ys ein ere we ecules eae 704 773 | 1,147 1,351 
Mlderitie ds soo. t kes ty ea Rea UE Ue. heab ees See ee ie ee eee 975 | 1,001 | 1,548 1,682 
ein ets ete oe a ee ee ce ee ee See ee 1,269 | 1,245] 1,949] 2,014 
