June i6, 1923 
Watery-Rot of Tomato Fruits 
903 
In view of the foregoing evidence, it would seem that the pressure 
theory of cell wall penetration by fungi is not so well supported as the 
enzym theory. 
DISTRIBUTION OF THE) FUNGUS 
As this physiological form of Oospora lactis has been isolated frequently 
from tomato fruits shipped from the Gulf States, it is probably common 
in at least several of the Southern States. It is difficult from the reports 
of the Bureau of Markets’ inspectors to estimate how often it really occurs 
in shipped tomatoes, as they report all such rots as “soft rot.” It was 
found to be common at the Government Experimental Farm, Arlington, 
Va., and in gardens in the vicinity of Washington, D. C., where no doubt 
it has carried on its parasitic activities for some time, but has been over¬ 
looked because of the similarity of the rots produced by it and Bacillus 
carotovorus and the not infrequent association of the two organisms in 
the same fruits. 
possible means of control 
As this fungus infects tomato fruits quite readily between 9° and 32° C. 
and can infect them at temperatures ranging from 2° to 37.5°, the prac¬ 
ticability of controlling it by means of low temperatures seems doubtful. 
Some experiments were made to determine the effects of antiseptics 
on the control of this organism. The fungus was immersed for 30 minutes 
in an aqueous solution of the antiseptic and transferred to sterile carrot 
decoction, in which, if it were still viable, it grew readily. The results 
are summarized in Table III. 
Tabi,^ hi .—Effect of antiseptics on the viability of Oospora lactis parasitica 
Antiseptic. 
Concentration of solu¬ 
tion. 
Subsequent growth 
in carrot decoction. 
Antiseptic. 
Water. 
Chlorid of lime. 
I 
40 
(a) 
400 
(a) 
s, 000 
300 
None. 
Potash alum. 
(a) 
I 
Considerable. 
None. 
Potassium permanganate. 
Copper sulphate. 
(a) 
I 
Good. 
Mercuric chlorid. 
None. 
Formaldehyde, 37 per cent. 
I 
Do. 
Water. 
Abundant. 
« Saturated. 
Immersing the fungus for 30 minutes in an aqueous solution of chlorid 
of lime 1140, potassium permanganate 1:400, formaldehyde (37 percent) 
11300, or mercuric chlorid i .*5000, prevented its subsequent growth, but 
a similar treatment with a saturated solution of potash alum or copper 
sulphate was ineffective. The resistance of this fungus to copper sul¬ 
phate—a fungicide of wide use—^is surprising. Although the experi¬ 
ments with this treatment were repeated several times, only negative 
action was obtained. 
Some expjeriments were also made on the use of the antiseptics as 
washes. Tomato fruits varying in maturity from green to ripe were 
lightly pricked in several places and submerged for 5 minutes in an 
aqueous suspension of Oospora spores, then drained, washed in an anti¬ 
septic solution for 30 minutes, and placed in moist chambers. From 20 
