New Yorx AGRICULTURAL EXPERIMENT STATION. 175 
this may not have been wholly due to the powdery mildew. The 
plans were affected to a considerable extent also by downy mildew, 
Plasmopara cubensis (B. & C.) Humph. 
Since no perithecia were found the identity of the fungus is a 
matter of conjecture. On his mildewed greenhouse cucumbers 
Humphrey found the perithecia of Hrysiphe cichoracearum D. C. 
According to Frank’ Sphaerotheca castagnei Lev. occurs on 
eucumbers in Europe, but the most common powdery mildew of . 
cucumbers and other cucurbits in Europe is known only in the 
conidial form which passes under the name of Oidiwm erysiphoides 
Fr. Sturgis’® assumes that the powdery mildew of the cucumber 
is identical with the one occurring on squash, but to us this appears 
extremely doubtful for the following reasons: The powdery mil- 
dew is common in this country on squash but on cucumber it is 
rare. During the past two seasons it has been abundant on both 
squashes and pumpkins in the vicinity of Geneva, but in no case 
have we observed it upon cucumbers, although cucumber vines 
have frequently been seen growing among mildewed squashes and 
pumpkins. Vice versa, on Mr. Estabrook’s farm at Athens, Pa., 
a squash vine running among the mildewed cucumbers was entirely 
free from, mildew. 
Cucumber growers need not be alarmed at the appearance of 
this new parasite. It is not likely to become epidemic and in case 
it should do so it will probably not be found difficult to control. 
il. DODDER ON CUCUMBERS UNDER GLASS. 
The numerous species of dodder, Cuscuta, may be expected to 
occur on a great variety of plants in the open air, but it is unusual 
for them to attack greenhouse plants. An interesting case of dod- 
der occurred in the Station cucumber-house last spring. In May, 
the writer observed a slender, yellow dodder thread twining about 
9 Frank, A. B. Die Krankheiten der Pflanzen. 2: 260. Eduard Trewendt, 
Breslau, 1896. 
10 Sturgis, W. C. Twenty-First Ann. Rept. Conn. Agr. Exp. Sta., 1897: 214. 
