Feb. 16, 1924 
Flag Smut of Wheat 
465 
Table IV .—The effect of soap solutions on the germination of spores of Urocysiis iriiici, 
11 months old , sown February 75 at from 16 0 to 22 0 C. 
Num¬ 
ber of 
dish. 
! 
J 
Medium. j 
Feb. 21. 
Feb.22 
55 
Dist. HoO. 
0 
O 
56 
58 
.do.I 
0 
O 
Ivory soap, 1:40,000. \ 
0 
0 
64 
Ivory soap, 1 :400,000 
0 
O 
70 
Ivory soap, 1: 4,000,000. . 
0 
0 
59 
Pot. palmitate, 1:40,000. 
o 
O 
65 
Pot. palmitate, 1:400,000. 
j 0 
0 
*7 1 
Pot. palmitate, 1: 4,000,- 
000. 
1 
| O 
0 
60 
Sod. stearate, 1:40,000.. . 
° 
O 
66 
Sod. stearate, 1: 400,000.. 
1 O 
0 
72 
Sod. stearate, 1:4,000,000. 
! 0 
86 
61 
Pot. stearate, 1:40,000.. . 
o 
0 
67 
Pot. stearate, 1:400,000 .. 
i 0 
0 
73 
Pot. .stearate, 1:4,000,000. 
t 
0 
0 
62 
vSod. oleate, 1:40,000 
0 
l 0 
68 
Sod. oleate, 1:400,000 . . . 
i 0 
0 
74 
Sod. oleate, 1:4,000,000.. 
0 
0 
63 
Sod. palmitate, 1:40,000. 
0 
0 
69 
Sod. palmitate, 1:400,000 
0 
0 
75 
Sod. palmitate, 1:4,000,- 
000. 
1 ! 
0 
: 
0 
Percentage of germination on— 
Feb. 23.) 
1 
Feb. 24. 
Feb. 25. 
Feb. 26. 
Feb. 27. 
0 
0 
| 0 
0 
0 
0 
O 
i 0 
8 
0 
10 
i 
0 
' Trace. 
| 
. j 
0 
: Trace. 
| 
. | 
1 
0 
' 80 
1 
I 
j 
0 
i. 
1 
0 
j 
. 
i 
0 
JO 
0 
! 0 
0 
Trace. 
0 
! 9 2 
i 
j O 
10 
! w 
0 
1 15 
1 0 
i Trace. 
!. 
! 0 
1 0 
! O 
1 
0 ! 
i 
0 
1 ° 
1 20 
i O 
i Trace. 
1 
! 
| © 
t 
0 
0 
0 1 
Trace. 
i O 
| 
1 0 
I 0 
0 ! 
1 
0 
I O 
! 
0 
i 
0 ! 
I ; 
1 0 ! 
i ; 
1_ 1 
0 
The observations were made with a Du Noiiy surface tension apparatus 
in which the force necessary to pull a ring from the surface of the liquid 
was measured as a function of the torsion of a wire. No significant dif¬ 
ferences were observed between the surface tension of water and that of 
benzaldehyde in a concentration of 3 parts per 2,000,000 parts of water. 
The surface tension of butyric acid in water solution (1 part per 100,000) 
differed from that of water by only 3 to 4 dynes. It would appear that 
the surface tension of these fluids when measured against air is not a sat¬ 
isfactory criterion for comparison of their effect on the germination of 
the spores of Urocystis tritici. 
Stiles (46) has extensively reviewed the evidence on the nature of per¬ 
meability of plant tissues and has reported further experiments on the 
action of alcohols and certain electrolytes on the permeability of such tis¬ 
sues. Both the cell wall and protoplasmic cell contents are concerned in 
the process, but the constitution of the protoplasm is of fundamental im¬ 
portance. Protoplasm is considered primarily as a complex colloidal sys¬ 
tem in which the constituents are continually changing their relation¬ 
ships in reference to one another as a result of the action of various 
physical and chemical forces to which they are exposed. 
In such a system surface action is of paramount importance, and sur¬ 
face phenomena are considered to play an important part in changing the 
permeability of the cell. In discussing the subject of surface tension, 
this author calls attention to the fact, already noted by Koltzoff and 
Vernon, that, although the surface tension of a solution be measured 
against air, in the experiment the surface tension is acting against 
the outer layer of protoplasm, and it is not possible to determine 
the surface tension between two immiscible liquids by knowing only 
the surface tension of each against air. 
