474 



BOTANICAL GAZETTE 



[DECEMBER 



less than from the free water surface. We are led, then, to the 

 conclusion that transpiration from these plant surfaces occurs 

 both by day and by night, but that the day transpiration is greatly 

 in excess of that taking place at night. These observations are 



Date 



Aug. 



Sept 



30 

 30 



3i 



3i 

 1 



1 



2 



3 

 3 

 4 

 4 



8 



8 



9 



9 

 10 



10 



13 

 13 



15 

 15 



19 



55 efl" 



I 



< 



12 

 12 

 12 

 12 

 II 



13 



24 



12 

 12 

 II 

 12 



8 



14 



IO 



13 



9 

 IS 



11 

 13 



8 

 13 



13 



TABLE V 

 Comparative evaporation in 191 i 



Conditions 



Day 

 Night 



Day 

 Night 



Day 



Night 



Day and night 



Day 

 Night 



Day 

 Night 



Day 



Night 



Day 

 Night 



Day 

 Night 



Day 

 Night 



Day 

 Night 



Night 



Totals for an 

 period of 270 

 water added) , 



approximate 

 hours (cc. of 



Amounts of evaporation from the tanks (cc. of water added) 



I 





4160 

 IOOO 



3050 

 60O 



5IIO 



925 

 7560 



4850 



IO5O 



5680 



780 



1885 

 440 



324O 

 640 



3030 

 550 



464O 

 I430 



3880 

 700 



I5OO 



56,700 



en 



I 



■j~. 



3590 

 780 



2405 

 540 



3410 

 860 



5730 

 4300 



935 

 4200 



730 



1 495 



375 

 2285 



580 



2025 



460 



3620 



2275 

 655 



,1360 



£T3 



2860 

 680 



I905 

 56o 



3200 

 870 



S07S 

 3090 



920 



4060 



64O 



1885 

 340 



1915 

 400 



1735 

 210 



2800 



1240 1220 



2425 

 575 



1285 



43,850 38,650 



I 



- 



- 



3085 



I 145 

 2IOO 



520 



3360 



8OO 



5725 

 3945 



975 

 354o 



725 



1250 



380 



2250 



530 

 1940 



44o 



345o 

 1280 



2570 

 740 



1250 



42,000 



3 



a =3 



O 



1630 

 680 



745 



595 

 1300 



660 



3120 

 i960 

 1030 

 1880 

 710 



I 



400 

 240 

 580 

 5io 



535 

 270 



1700 

 1 195 



700 

 5 10 



1350 



>> 





ii75 

 620 



490 



520 



790 



455 

 2310 



1415 

 830 



1345 

 630 



265 

 210 



35o 



465 

 300 



175 



1 130 

 1030 



485 

 43° 



1 1 20 



o 00 



o 



1095 

 600 



585 



575 



950 



575 

 2780 



1545 

 830 



1270 

 655 



255 



225 

 360 



5io 



365 



220 



1180 

 1050 



53° 

 380 



1200 



2 M 



u 



1420 



615 



5i° 



575 



835 



655 

 2880 



1690 



1030 



i55o 

 720 



265 



250 



35° 

 600 



345 

 240 



1390 

 1 180 



440 

 470 



133 



22,300 16,540! 17,735 J 9..34° 



in accordance with the results obtained by Clapp (3) and others 

 with land plants, in which it has been found that land plants 

 transpire principally during the day and only feebly if at all at 

 night. 



