322 BOTANICAL GAZETTE [APRIL 
possibly to be correlated with their peculiar behavior, and it may 
be suggested that such permanent structural retardation of water 
loss as is present in the foliage of such types may have to do with 
preventing a marked decline in leaf moisture by day. Such plants 
‘seem worthy of further study in this connection. The other excep- 
TABLE II 
AUGUST 21-22, I910 
EVAPORATION PERCENTAGE OF MOISTURE 
Physalis Nicotiana Euphorbia Trianthema Tribulus 
reas ce. Sa eS BSE are essa iS cea hE Res BU ese porn sina Pee aaa ert DAUR ats neg eee nts Rte onTUEy 
Period | per hr. | of test of dry f |ofdry| of | ofdry| of | ofdry| of | ofdry| of 
sub- entire | sub- entire | sub- entire | sub- | entire | sub- | entire 
stance | weight | stance | weight | stance | weight | stance weight | stance | weight 
(A.M.) 
4- 5 | 0.06 be Pe Po Soe, OS fs ah re .. | 435-6) 81 
58 1.0.00 ie eos: Pe Pees ee, A Ces Sei reas ee vas [oie s = 
6— 7 | 0.50 74 BAO a BH bees es 551.0) 85 (1203.0 92 |.2..-. 
F841 .20 POET (eee Saran eae ge PRON Cade eer hee pees es te et es 
8 9} 1.02 9 | 865.5] 90 | 435.0] 81 Sat. Gi. 34. [107.01 02> |. 382.51. 78° 
a ee ee tig rh eek oi oes 
TO“11| 2.40 Oe eS ee er ee 
Re ee ier as ee i 1 eo ee. 
(P.M.) 
12% fee 1078.5) 67 {| 423.3) Sx .| 433.8] 8x* 758.0] 89* | 378.8) 79 
See ee een ere alte Racor uM wa lCr Ey! aly Gee ke ey te Spe dice 
5 68 4 1660.61 82" foo oy: ee ee oP eS [eae 
3-4 | 2.70 pel Peas eaor ee ea ee tet naa Saar So up oe ry ae 
ae 2.70 5 703.4} 87 | 392.5} 80* | 485.5] 83 326.2), 80° 1420.51) St 
5- 1.92 us pee ara Sea fy eee Fer anis Wa pera Panes Ven pi sc” Mewes oe 
6- 7 | 1.20 er OO fee eS ee 
Ce er Se ee 
8-9 | 1.20 B56 9), gO" 1... SG Se 1: 430.6) 81 
ee ee ee ee es ee Le ow eb ep 
Se a ee oe 
AR eae ee ene ey ye th ie owe che. a leisy clo 
(A.M.) 
Se ee eee ee te oh ee pl occ ep pe 
I- 2 | 0.42 Seay Te Snes ee ee ee eee te ee oe oe 
2—- 3 | 0.18 3 Rete Oe to ihe od at 
tion to the usual behavior is that of Physalis (table IV). For this . 
species we have two cases exhibiting the usual behavior (besides 
the preliminary test, which makes three), and it is noted that the 
exceptional case occurs on a day with very low evaporation. 
Table V presents a summary of the data of the preceding tables. 
The minimum and maximum water content and the hours at which 
