May 31,1924 
Common Brown Rot of Fruits 
957 
of filter paper and a drop of stain solution (eosin or safranin) was’added. Material 
treated in this way was examined with the following results: 
Asci.—The asci are cylindrical to club-shaped with rounded apices. They 
taper gradually in the lower half to the point of attachment. The pore stains 
blue with iodine, and is brought out with great clearness by the use of this 
reagent. The 17 measured ranged from 117.8 to 161.5 p in length and from 5.7 
to 9.5 in width. 
Ascospores. —Ascospores, eight in number, hyaline, nonseptate, in upper half 
of the ascus. They may be arranged end to end or, as in somejcases, with their 
long axes at an angle to the long axis of the ascus, that is, seriate, ellipsoid in 
shape, some with quite pointed ends but generally with rounded ends, hyaline. 
Of 100 spores measured, the lengths ranged from 6.8 to 13.1 /u, with the greatest 
number 10.2 a*. The widths varied from 3.4 to 6.8 n with the greatest number 
5.1 /*. 
Paraphyses. —Paraphyses filiform, hyaline, septate, ranging from 119.7 to 
142.5 ju long and from 1.9 to 3.8 n wide. The tip was rounded and in some 
cases slightly swollen. Some were branched. Only five paraphyses were meas¬ 
ured, due to great difficulty in determining whether or not the ones seen 
on the slides were of full length or broken. The ones measured were quite 
certainly intact and of full length. For purposes of comparison the following 
measurements of Sclerotinia are given. It should be noted that these measure¬ 
ments, regardless of the names given, are of Sclerotinias from stone fruits in 
America. 
Investi¬ 
gator 
Date 
Name given to 
fungus 
Host 
Asci 
Ascospores 
Winter. __ 
1883 
Ciboria fructicola . 
Peach... 
130 to 160 X 8 to 8.5. 
10 to 12.5 X 4 to 5.5. 
Reade_ 
1908 
Sclerotinia fructigena . 
...do. 
125 to 215 X 7 to 10. 
10 to 15 X 5 to 8. 
Pollock... 
1909 
Sclerotinia fructigena 
Stone 
fruits. 
130 to 179 X 9.2 to 11.5... 
11.4 to 14.4 X 5 to 7. 
Matheny. 
1913 
Sclerotinia cinerea ... 
Peach... 
135 to 190 X 6.9 to 10.5... 
10.5 to 14.5 X 5.2 to 7.5. 
Matheny. 
1913 
Sclerotinia cinerea _ 
Plum... 
135 to 173 X 6.8 to 10.8... 
8.3 to 14.2 X 5 to 7.4. 
Roberts. _ 
1920 
Sclerotinia cinerea _ 
Peach... 
152 to 176 X 8 to 10_ 
6 to 15 X 4 to 8. 
Dunegan. 
1922-1923 
Sclerotinia cinerea _ 
...do_ 
130 to 186 X 5.7 to 13,3... 
9.5 to 14 X 5.7 to 7.6. 
Dunegan. 
1924 
Sclerotinia fructicola 
(Winter’s type 
material.) 
-.do. 
117 to 161 X 5.7 to 9.5.... 
6.8 to 13.1 X 3.4 to 6.8. 
The table shows a series of measurements, exclusive of Rau’s material, in 
which the range for asci is from 125 to 215 ju in length and from 5.7 to 13.3 u in 
width. For ascospores the range is from 8.6 to 15 m in length and from 4 to 
8 m in width. These measurements agree fairly well with those of the type 
material of S. fructicola. That there should be some variations is to be expected 
when one considers the differences in the technique employed and also from the 
fact that Winter himself used dried material (Rau collected it in May, and 
Winter published his description in the September number of Hedwigia of the 
same year, namely, 1883), and that the measurements made by the present 
junior author were of material that had been dry for a little short of 41 years. 
It therefore seems certain that in 1883 Rau collected and Winter described the 
species of Sclerotinia which Norton in 1902 showed to be the ascogenous stage 
of our common brown-rot fungus. 
Since, as previously noted, it has been well established that the name S. fruc - 
tigena belongs to a European species that is distinct from the American, only 
the following binominals need be considered: Sclerotinia cinerea (Bon.) Schroter, 
Sclerotinia fructicola (Wint.) Rehm, and Sclerotinia americana (Wormald) Norton 
and Ezekiel. 
