326 
Journal of Agricultural Research 
Vol. VIII, No. 9 
Choanephora cucurbitarum (Berk, and Rav.) Thaxter 
Choanephora cucurbitarum (Berk, and Rav.) Thax., 1903, in Rhodora, v. 5, p. 97-108, pi. 46. 
Rhopalomyces cucurbitarum Berk and, Rav., 1875, in Grevillea, v. 3, no. 27, p. 109. 
Rhopalomyces elegans, var. Cucurbitarum Marchal, 1893, in Rev. Mycol,, ann. 15, no. 57, p. 11. 
Aspergillus cucurbiteus Curtis, in Harvard Herbarium. 
Choanephora awmama Moller, 1901, Phycom. u. Ascom., p. 18, pi. i, fig. 1-4. 
Sporangia pendula, globosa, solitaria, polyspora, nigra, 35-160 n diam.; stipite 
nitido-violaceo; columella globosa; sporis ovoideis vel ellipsoideis, levibus, brunneo- 
rufis 18-30X10-15 fx. utrimque interdum atque lateribus penicello ciliorum auctis; 
ciliis 25-45 m longis. Condidiophoris usque 6 mm. longis, nitido-violaceis; apice 
yescicula unica vel pluribus capitatis muriculatis terminatis; conidiis in vescicula 
capitatim msertis ovoideis longitrorsum striatis, brunneo-rufis, appendicula basilare 
hyalina, 15-25X7.5-11 m. Chlamydosporae globosae vel oblongo-ellipsoideae. Rami 
zygosporae arcuati, zygosporis inaequilateralibus, unico globulo olei genente, 50-90 n 
diam. 
Hab. in fructibusque floribus vivis Cucurbitae peponis ac in floribus languidis 
Hibisci esculenti, H.coccinei, H. syriaci, Gossypii herbacei, Cucumis sativii aliisque 
malvacearum, Americae Bor., atque in petalis adhuc stantibus Hibisci aliisque plantae 
partibus dejectis, Blumenau brasiliae. 
PATHOLOGICAL ANATOMY 
Diseased tissues from squash fruits and flower pedicels were fixed, sec¬ 
tioned, and stained for this portion of the study. Mycelium was found 
to be present in all of the tissues that were involved in softrot or wetrot, 
with no evidences of disintegration in advance of the mycelium. It is 
both intercellular and intracellular, as shown by Plate 85, F, K t figure F 
representing the invaded tissue of the flower pedicel and K that of squash 
fruit. Parasitism appears to be of the necrotic type, with little or no 
transformation of the cell wall substance. Growth of the fungus on cel¬ 
lulose agar gave no evidence of the secretion of cellulase. Evidence of 
the presence of cellulase and cytase was further sought, with negative 
results in 14-day-old cultures of C. cucurbitarum on sterilized squash 
fruits. The fluid from these cultures was filtered through a Chamber- 
land filter and pieces of raw fruits were introduced under aseptic condi¬ 
tions into this sterile filtrate. 
DISSEMINATION OF THE FUNGUS 
A microscopic examination of the inner surface of the corolla tube and 
of the filaments of the stamens revealed the fact that conidia of C. cucur¬ 
bitarum are commonly present in open squash flowers. Thirty of the 
35 flowers which had opened on the morning of July 6, and which were 
examined in the afternoon of that day, contained conidia. On the after¬ 
noon of the 7th, conidia were present in all the flowers examined,—27. On 
the 8th, 7 flowers were picked before 7 a. m., and all had conidia within 
them. On the 10th, conidia were present in 25 flowers which had not yet 
closed. Since various species of bees so commonly visit squash flowers, a 
limited number were examined to determine whether they were instru¬ 
mental in distributing the conidia. The bees, when captured among the 
