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size but were yet green; some showed rot in various degrees, and a 
few were covered with spores. Those which were brown but with 
no spores, when placed in a moist bell jar over night (twelve hours) 
developed them in profusion. 
When the cherries ripened, those touched by the dry mummied 
ones still clinging to the tree soon developed rot, these transmitted 
it to others in contact with them, and thus a whole cluster would 
be brought to decay. The rotting ones produced, especially if the 
weather was somewhat damp, a thick coat of spores. The spores, 
both from the freshly rotted and the mummied cherries, were dis- 
persed by the wind over the entire crop, and led to a variable amount 
of rotting. The results were the most marked shortly after a light 
shower or mist, or during very damp days, and particularly at the 
point of contact of two fruits, where a drop of water was held long 
enough to permit the fungus to germinate and become established. 
There can be no doubt of the power of the germinating threads of the 
fungus to penetrate the uninjured skin of the fruit, at least of plums 
and cherries, although in experiments on peaches Peck* concluded 
that this was not possible; as also did Smitht who used apples, and 
Halliert thought the fungus only entered through rifts or stomata. 
Tt seems to me these failures may have been due to neglect in put- 
ting the fruit experimented on in a sufficiently damp atmosphere. 
Just here lies the reason why this fungus does not annually destroy 
the total crop of cherries and plums, even the flowers, foliage and 
perhaps the trees themselves—the lack of a sufficiently and continu- 
ously moist atmosphere; my experiments certainly warrant this con- 
clusion, and ordinary observation will to some extent confirm it, for 
every grower knows how much the rot is increased by moist weather 
and light rains after the fruit has reddened, far beyond what can be 
accounted for by the fungus gaining entrance through injured spots. 
Although the dead and dry fruit upon the tree only has been 
spoken of as a source of infection, it is not the sole one, and often 
may not be the chief one. Fallen fruit supports the fungus to an 
unlimited extent, and also that in cellars and pits. An interesting 
estimate was made of the rapidity of spore production under fayora- 
ble circumstances. A few spores (not counted) were inserted beneath 
the surface at a single point on each of several ripe black raspber- 
ries, which were placed under a moist bell jar in a living room. At 
the end of twenty-four hours a careful estimate placed the number 
of spores formed at each center of infection at five thousand. It 
took but six days to entirely clothe the berries with a close felt of 
spores, which of course were too numerous for computation. 
One would suppose there could be no doubt of the destructiveness 
of this rot, and yet a curious claim has been started for it, as pos- 
sessing antiseptic and fruit preserving qualities. This was first pub- 
lished by Von Thiimen |, in a Vienna agricultural newspaper in 
1875. His observation was that pears lying on the moist earth under 
the tree, well covered with Oidium, did not decay after weeks of 
*Thirty-fourth Rep. N. Y. St. Mus, Nat. Hist., p. 35. 
*Gardeners’ Chronicle, XXIV, p. 52. 
**Quoted by Frank, Krankh, d. Pflanzen, p. 615. 
*Landw. Wochenblatt, No. 41; Fungi Pomicoli, p. 23. 
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