ANTHEACNOSE OF CUCURBITS. 23 



sibility of confusion with infection from any source other than badly 

 diseased cucumbers, the list of hosts is increased by the addition of 

 several varieties of cucumber, two varieties of muskmelon, citron, 

 seven Lagenaria gourds, and Cucumis anguria var. grossulariae. Ex- 

 posure to natural infection in an experimental field at Plymouth, 

 Ind., in 1916 adds to this list of hosts Momordica balsamina and M. 

 charantia. 



Repeated attempts to inoculate 6 varieties of squash, 2 varieties 

 of pumpkin, and 12 varieties of Cucurbita gourds yielded only nega- 

 tive results, as did also attempts to inoculate Echinocystis lobata, 

 Bryonopsis laciniosa, 3 Momordica species, and a species of Luffa. 



To determine just how the fungus might react toward squash, 

 drops of a spore suspension were placed on the leaves of a squash 

 plant in the greenhouse. Except for a slightly yellowed area on one 

 old leaf no lesions developed. Microscopic examination of material 

 from this yellowed area, fixed according to methods to be described 

 later, showed that the fungus had penetrated the epidermal cells but 

 had gone no farther. 



Exposure to the same epidemic of natural infection above noted 

 gave negative results in the following: Early Russian cucumber, 

 Giant Pera cucumber, pumpkins (2 varieties), squash (6 varieties), 

 Bryonopsis laciniosa, Luffa sp., and 16 varieties of Cucurbita gourds. 



Using cultures from watermelon, Sheldon (46) was unable to infect 

 squash, pumpkin, and wax-bean plants. Edgerton (12) and Tauben- 

 haus (51) were unable to infect apple fruits. The latter also secured 

 no infection of sweet-pea plants. In the present investigation no 

 success was obtained in an attempt to infect apple fruits. Inocula- 

 tions on five varieties of beans in the field gave negative results, as 

 did also exposure of these varieties to natural infection during an 

 entire season. 



Following is a list of susceptible host varieties as noted during 

 the course of this investigation: 



Cucumbers. — Heinz Chicago Pickling, Nichols' Medium Green, Thorburn's Klon- 

 dike White Spine, Japanese Climbing, Lemon, Boston, Jersey, Arlington, Milwau- 

 kee, Livingston, Emerald, Davis Perfect, Improved Long Green, Early Fortune, 

 Telegraph, Vaughan's Prolific, Carter Model. 



Muskmelons. — Banquet, Long Yellow, Shumway Giant, Orange Christiana, Hy- 

 brid Casaba, Hackensack, Rocky Ford, Winter Pineapple, Banana, Mango. 



Watermelons. — -Watson, Pierson, Bed-Seed Citron. 



Lagenaria gourds. — Bottle, Dishcloth, Knob Kerrie, Dipper, Hercules Club, Sugar 

 Trough, Calabash. 



Other cucurbits. — Cucumis anguria, C. anguria var. grossulariae (fruit only), C. 

 dipsaceus, C. melo var. flexuosus, C. melo var. dudaim, Trichosanthes colubrina, 

 Benincasa cerifera. Reported on Momordica balsamina and M. charantia. 



