434 BOTANICAL GAZETTE [DECEMBER 
gratuitous supposition that plants in general may be found to 
average up, in their sensitiveness to light intensity, as did the 
three which happened to be used in these tests. 
TABLE VII 
| COEFFICIENTS OF CORRECTION AVERAGE 
INSTRUMENT 
Plant Test I | Test II | Test III | Test IV | For plant} For instr. 
Physal. =... Tiss) oT. 40.) res TAG | 2230 
Brown atm..... mateo. 0.92 0:73 0.97 T.18-) 0:65 1.09 
Martyn. <2... ee Sar 1.04: f° 6:98 4 “T0Gr 7 
Physah 2. E41 r6e|. 6.864: 3.471. 83 
Black atm..... 2 Ct ee 1.09 | 0.85 | 0.74| 1.15 | 0.96 |} 1.06 
Martyn..... Hee abs 0.79 | 0.96| 0.88 
: PUyHe 2 2. I.92| 1.60 “a.e2 | 1.61 | 1.59 
White atm..... pt 2 RO aes ¥.48 | 6.83 | 1.04 | 1.63 | 1.99 (pee 
Martyn..... wees ven ¥.12 40:) 2224 
Physal. ..... ee eee 0.78 | 0.56| 0.67 
Integr: 2... Maths css: ave bo. 41 3.06 1-046 p 0.567 ee 
Martyn..... Oo. 72 | 0.98 | 6:58 
Physal...... 0.52 23 |:.0.38 
**Solio”’ paper. . AA, yc, ) 0.18 | 0.31 | (9-33 
Martyn..... 0.47 15 | :O:gt 
Physabo os: ae PIS; 0:56 | 0.47 | 8.52 
Wynne paper .. PANU ys ee Niet 0.48 | 0.39 | 0.44 0.46 
Martyn..... eS ciga [om §E 1. 0.32) Oras 
Physal.. 3.5: 62 | 0.45 | 9.54 
Black therm... . Rann See 0.52 | 0.36} °o. 0.47 
Martyn..... 156 |: 0.30 | 0-43 
Conclusions 
In the last section have been brought forward the results of an 
experimental attempt to determine what sort of corrections must 
be applied to the data furnished by the seven instruments tested, 
in order that we may obtain from these data the sun-shade ratios 
of the transpiration rates as actually exhibited by the different 
plants. Four tests, each furnishing two sun-shade ratios for each 
. plant, have been carried out. In all, we have eight tests for Physalis 
and the same number for Xanthium, but only four for Martynta. 
It is safe to assume that the full sunshine for the three days of this 
inquiry was approximately the same; all tests continued through 
