1042 
Journdl of Agricultural Research 
Vol. XXX, No. 11 
ous to cucumbers. After securing nega¬ 
tive results with three spiny forms, the 
writer was interested to discover that a 
fourth form derived from pea roots 
affected with the root-rot due to 
Aphanomyces euteiches Dr., and appar¬ 
ently different from the other three, 
attacked cucumbers with moderate 
vigor, the tissues becoming soft and 
watery. 
In considering means of controlling 
losses from cottony leak, it is unfor¬ 
tunate that no information is available 
concerning the incidence of original 
infections. Knowledge as to whether 
such infections take place in the field or 
subsequent to picking would appear to 
be of primary importance. As the 
progress of the parasite at lower tem¬ 
peratures is relatively slow, and extra- 
matrical development is reduced to 
small proportions in the absence of 
water of condensation and high humid¬ 
ity, attention to proper ventilation com¬ 
bined where practicable with refriger¬ 
ation might be expected to check the 
spread of the infection to stock in good 
condition at the time it was packed. 
The attention of students of plant 
diseases is directed to the very evident 
partiality of species of Pythium for the 
fruit of many Cucurbitaceae. Losses 
in the field due to their parasitism is 
undoubtedly more considerable than 
the paucity of references in the litera¬ 
ture might lead one to suppose. Parisi’s 
record {12) of the occurrence of P. 
debaryanum on the fruit of chayote 
(.Sechium edule Sw.) in the botanical 
garden at Naples in December, 1920, 
is pertinent in this connection. Not 
less interesting is the very recent 
report by McRae {10) of the associa¬ 
tion of strains of Pythium with the 
decay of Luff a acutangula Roxb., L. 
aegyptiaca Mill., Trichosanthes anguina 
L., and Lagenaria vulgaris Ser. in 
India, where these members of the 
Cucurbitaceae are grown as vegetables. 
SUMMARY 
Cucumbers grown in the Southeast¬ 
ern States have, on arrival at the 
northern markets, shown occasional 
losses due to a disease for which the 
term “cottony leak” is proposed. It 
is caused by a species of Pythium 
identified as Pythium aphanidermatum 
(Eds.) Fitz., the infection being com¬ 
municated from diseased fruits to 
adjacent healthy ones by copious pro¬ 
duction of extramatrical mycelium. 
The fungus is strongly parasitic on 
watermelons, on which host it is re¬ 
sponsible for one of the blossom-end 
rots widely prevalent in the Middle 
Atlantic States. On inoculation it is 
rapidly destructive to patty-pan, veg¬ 
etable-marrow, and summer crookneck 
squashes. 
The sorting out of cucumbers har¬ 
boring, the fungus and the lowering of 
humidity and temperature by ade¬ 
quate ventilation, combined possibly 
with refrigeration, are indicated as 
means for controlling the trouble. 
LITERATURE CITED 
(1) Atkinson, G. F. 
1895. DAMPING OFF. N. Y. Cornell Agr. 
Exp. Sta., Bot. Div. Bui. 94: 233-272, 
illus. 
(2) Bary, A. de 
1881. ZUR KENNTNISS DER PERONOSPOREEN. 
Bot. Ztg. 39: 521-530, 537-544, 553-563, 
569-578, 585-595, 601-609, 617-625, illus. 
(3) Butler, E. J. 
1907. AN ACCOUNT OF THE GENUS PYTHIUM 
AND SOME CHYTRIDIACEAE . Mem. Dept. 
Agr. India Bot. Ser., v. 1, no. 5, 162 p., 
illus. 
(4) Carpenter, C. W. 
1921. MORPHOLOGICAL STUDIES OF THE PY- 
THIUM-LIKE FUNGI ASSOCIATED WITH 
ROOT ROT IN HAWAII. Bui. Exp. Sta. 
Hawaii. Sugar Planters’ Assoc. Bot. 
Ser. 3: 59-65, illus. 
(5) Drechsler, C. 
1923. A NEW BLOSSOM-END DECAY OF WATER¬ 
MELONS CAUSED BY AN UNDESCRIBED 
species of pythium. (Abstract) Phy¬ 
topathology 13: 57. 
(6) Edson, H. A. 
1915. RHEOSPORANGIUM APHANIDERMATUS, A 
NEW GENUS AND SPECIES OF FUNGUS 
PARASITIC ON SUGAR BEETS AND RADISHES. 
Jour. Agr. Research 4: 279-292, illus. 
(7) Fitzpatrick, H. M. 
1923. generic concepts in the pythiaceae 
and blastocladiaceae. Mycologia 15: 
166-173. 
(8) Hawkins, L. A. 
1916. THE DISEASE OF POTATOES KNOWN AS 
“leak.” Jour. Agr. Research 6 : 627-640, 
illus. 
(9) Lehman, S. G. 
1921. soft rot of pepper fruits. Phyto¬ 
pathology 11: 85-87. 
(10) McRae, W. 
1923. REPORT OF THE IMPERIAL MYCOLOGIST. 
Sci. Rpts. Agr. Research Inst., Pusa 
1922—23 : 53—60. 
(11) Marchal, Elie, and Marchal, Emile. 
1921. CONTRIBUTION A L’feTUDE DES CHAM¬ 
PIGNONS FRUCTICOLES DE BELGIQUE. Bul. 
Soc. Roy. Bot. Belg. 54: 109-139, illus. 
(12) Parisi, R. 
1924. CONTRIBUZIONE ALLA MICOLOGIA DEL- 
L’lTALIA MERDIONALE . Bul. Ol to Bot. R. 
Univ. Napoli 7: 35-66. 
(13) SCHROTER, J. 
1893. saprolegniineae . Engler, A., and 
Prantl, K., Die natiirlichen Pflanzen- 
familien. Lfg. 93, Teil 1, Abt. 1,. p. 93- 
105, illus. 
(14) Subramaniam, L. S. 
1919. A PYTHIUM DISEASE OF GINGER, TOBACCO 
and papaya. Mem. Dept. Agr. India 
Bot. Ser. 10: 181-194, illus. 
(15) Ward, H. M. 
1883. OBSERVATIONS ON THE GENUS PYTHIUM 
(pringsh.). Quart. Jour. Micros. Sci. 23: 
485-515, illus. 
