52 
TENTH REPORT. 
the spring of 1906, the hopes which germinated the year before, were rudely 
killed. No success whatever had attended our effort, and no material 
result of value, either, excepting that a knowledge of how not to obtain the 
ascus stage was obtained. 
Connecting the information gathered from this experiment with a study 
of the conditions surrounding those specimens obtained the year before, on 
the plowed ground under the trees, the suggestion arose that there was a right 
place, and wrong places, in which to look for material. The right place is 
in the surface of the ground, among dead, long grass around and near the 
foot of the tree. Of those found in the open, on the naked ground, it was. 
observed that they were not on top of the soil, nor yet under ground, but 
half in and half out. On account of the fact that the old diseased fruit 
should be half in and half out of the ground, it is not frequently that spec- 
imens can be found on the open plowed ground, because rain, frost, and the 
like, render it very improbable that a fruit should be so situated the whole 
season. If underground, the fruits will rot; if above ground, they will dry 
out. But in sod, where the soil surface is not likely to be disturbed, and the 
old fruits are protected by the shelter of the grass, is the place where the 
ascus stage flourishes. 
From such well-sheltered plums, abundant material was obtained. The 
apothecia grow on ascophores two or three centimeters. long, and develop 
from the underside of the old plum, turning up around the side and assuming 
the erect form. At first, these apothecia and ascophores are nearly cylin- 
drical structures, but later, the end of the ascophore opens, and the well- 
known disk appears. These disks are sometimes as much as a centimeter 
across (see figure II. a) and often ten or fifteen grow from a diseased plum (see 
figure III.) In these apothecia are many thousands of asci and in each ascus 
eight spores. In one case, an estimate was made as to the number of asci 
in one of these apothecia, and it was found that there was probably not less 
than ten million. This would give eighty million spores produced from 
one old plum. From this it may easily be inferred that under a single plum 
tree, or on a few square feet, there might be spores enough to infest a whole 
orchard. 
I might say that I have never found specimens of peach fruits affected 
with the Sclerotina, partly because in the vicinity of East Lansing, few peaches 
are grown. I presume, however, that where peaches are grown, and where 
Monilia is common, there will be plenty of material. 
The supplying of laboratory material for study has been kept in mind, 
because of the suitability of it for student study, but another important 
deduction might be made from the investigation. 
In view of the fact that this fungus has such a well-developed and vigor- 
ous winter stage, and in view of the fact that it is so destructive and so com- 
mon in orchards, some little success might be expected to follow a vigorous 
and systematic plowing under, or otherwise destroying, the old affected 
fruits. Knowing that the ascus stage does not develop on old fruits which 
have been buried, it should be comparatively easy to get rid of the winter 
stage by turning down all the old fruits around the trees. As has been 
pointed out, it is also highly important that no grassy patches should be 
allowed to grow up around the base of the trees. As orchards are cultivated 
frequently by using horses, and as the plow can not be brought close enough 
to the tree to turn over all the soil, there is left a lens-shaped tuft with the 
tree as the center upon which the grass and weeds grow and form a splendid 
breeding place for the winter stage of this fungus. 
