CYLINDROSPORIUM ON STONE FRUITS 
inoculations were made during the early spring of 1912 and 191 3. 
The inoculations were all made in the greenhouse and mostly before 
the ascospores had developed outside. 
Species of Prunus Employed in the Inoculations. — The plants used 
for inoculating in 191 2 were imported seedlings of mazzard (P. avium 
furnished by the J. B. Stewart Nursery Co.) and small trees of P. 
serotina obtained from a nearby thicket. These were cut back to mere 
stubs, dipped for a few minutes into a 7 per cent CuSO-i solution, 
planted in small pots, and set in the greenhouse. 
In 1913 these plants were given the same treatment and used 
again. About 50 trees each of P. virginiana and P. pennsylvanica 
and 15 of P. americana obtained growing wild in this region; 50 
mahaleb cherry and 50 myrobalan plum trees furnished by the Green- 
ing Nursery Co.; 50 sour cherry (Early Richmond) and 50 peaich 
(Elberta) trees bought from a local nursery; and 100 plum trees, 25 
each of P. domestica (several varieties) , P. americana (several varieties) , 
P. hortulana (several varieties), and P. insititia, furnished by the 
Horticultural Department of the Geneva Experiment Station were 
given the same treatment. 
The trees were cut back so as to give vigorous healthy leaves for 
inoculating and also so they could be covered with bell-jars when this 
was desirable. They were dipped in the CUSO4 solution to kill any 
conidia of Cylindrosporium as well as spores of other fungi which 
might interfere with the results of inoculations, although in so far as 
Cylindrosporium is co icerned sterilization was probably unnecessary,, 
since all observations indicate that the conidia are very short lived 
and are unlikely to live over winter. None of the plants were ever 
attacked by Cylindrosporium unless inoculated, although often kept 
as checks under conditions very favorable for infection had conidia 
been present. 
The plants when used for inoculation had vigorous shoots with 
usually 12-50 leaves. The myrobalan plums however were so slow 
in starting that only a few small plants were ready when the last 
inoculations were made. 
Inoculations with Conidia. — The first series of inoculations was 
made for the purpose of determining the conditions most favorable 
for infection. Four plants of mazzard cherry were inoculated with 
a pure culture of Cylindrosporium from the same host species. The 
conidia were shaken up in a small amount of sterile water which was 
