276 BOTANICAL GAZETTE [APRIL 
of dry matter produced by plants growing in different nutrient solu- 
tions has recently led Mazé™ to conclude that under the same 
aerial conditions the quantity of water transpired per unit of dry 
matter produced is constant and independent of the nature of the 
nutritive solutions or of their concentrations or of the state of 
development of the plant. It is needless to state that this conclu- 
sion could hold good only for solutions which contain all the neces- 
sary nutrients and which are not otherwise injurious to the growth 
of plants.” 
TABLE VII 
TRANSPIRATION PER SQ. DM. OF LEAF SURFACE DURING LAST FIVE DAYS OF GROWTH © 
OPEN 
Average hourly 
(ee te) Transpiration per 
No. of plant | Le _— pit rte a i lst st five piration sq. d surface cd let sue 
in . 
ty as Saran 22,026 10,941 49.67 0.414 
s, Geers hee stem 19,454 10,158 52.22 0.435 
iy cealng es oie 23,550 11,230 47.69 0.397 
Cee 20,335 10,376 51.02 0.425 
9 ae 21,300 10,936 51.34 0.428 
O sips 989 9,755 6 0.377 
oe ee 
Average 21,442 OOS bev Car asieat 0.412 
SHADE 
te eS 
beet ars 27,89 8,658 31.04 0.259 
oes. 27,461 8,332 30.34 0. 253 
tA ee 29,026 8,791 30.29 wegen 
icp 29,116 6,930 23.80 0. 198 
6.57 31,163 7,236 23.22 0.104 
BOs reece 31,867 7,224 22.07 0.189 
Average ... 29,442 Pee ee tee 0.224 
The relative transpiration per unit area of leaf surface is given 
in table VII. As has been stated, the figures are based on the tran 
spiration of the last five days. This table brings out the relative 
leaf areas of the plants grown under the two conditions. The 
a relation qui eng entre l’eau évaporée et le poids de matiere 
weil pres par le mais. Compt. Rend. 156:720-722. 1913- 
= That other conditions, such as ane ciency or excess of mineral nutrients, gd 
limit production while transpiration continues has been Seana! pointed pay Be 
agricultural literature: HELLRIeGcEL, H., Beitrige Naturwi Grundlagen A 
baus Braunschweig. pp. 628-635; Von SEELHORST, Jour. Landw. 47:369-378- 1899- 
