287 
OBSERVATIONS ON A DISCOMYCETE FOUND 
ON MEDLAR FRUITS. 
By H. Wormald, D.Sc., Research Department, South-Eastern 
Agricultural College, Wye, Kent. 
In 1920 the present writer* recorded the occurrence in this 
country of a fungus found associated with, and apparently the 
cause of, a leaf blotch of Medlar trees (Mespilus germanica L.). 
The fungus appeared on the upper surface of the diseased leaves 
in the form of grey tufts which were often confluent in lines 
along the principal veins and consisted of chains of almost 
spherical conidia; these conidia were connected by the slender 
fusoid bodies known as “disjunctors.” 
On comparing this fungus with the description and figures 
given by Schellenbergt it was evident that it was the conidial 
stage of Sclerotinia Mespili. That author found the apothecial 
stage of the fungus on the mummied Medlar fruits. He stated 
that these mummies were the result of infection brought about 
by the transference, by insects, of conidia from diseased leaves 
to the flowers. 
During the latter half of April and the first fortnight of May, 
1920, specimens of the leaf blotch were sent to Wye College 
from five localities, four in Kent, the other in Somersetshire. 
At two of these a search was made under affected trees for the 
apothecial form of the fungus. On the trees and also on the 
ground beneath them were found small dried up undeveloped 
Medlar fruits but in no case could apothecia be discovered on 
these. Some of these mummies were collected towards the end 
of April (1920) and brought to the College where they were 
placed on the surface of ordinary garden soil in two plant pots; 
in one pot were placed those collected from the ground, in the 
other those taken from the tree. The pots were then left exposed 
in the open. 
A microscopic examination of a number of these mummies 
showed the presence of hyphae in the tissues, and almost in- 
variably numerous, minute, spherical, spore-like bodies (micro- 
conidia or sporidia) could be obtained by placing scrapings from 
the surface of the fruits in water. Cultures were obtained from 
* Wormald, H., On the Occurrence in Britain of the Conidial Stage of 
Selerotinia Mespili Schell., Ann. Appl. Biol. vir, Nos. 2 and 3, pp. 173-6, 
Dec. 1920. 
¢ Schellenberg, H. C., Ueber Sclevotinia Mespili und Sclerotinia Artae, 
Cent. fiir Bakt. Abt. 2, Bd. xvu, pp. 188-202, 1907. 
19—2 
