288 Transactions British Mycological Society. 
the internal mycelium and these resembled in their mode of 
growth others obtained from conidia taken from the leaves. In 
such cultures micro-conidia similar to those obtained from the 
surface of the mummies were invariably produced. No macro- 
conidia, i.e. similar to those which develop on the leaves, were 
formed in any of the cultures. 
When the pots were examined about the middle of the fol- 
lowing February (1921) it was seen that on some of the mummies 
in the pot containing those collected from the ground, there 
were present rounded villose brownish outgrowths, I to I-5 mm. 
in diameter; by March 1 these outgrowths had become more 
or less conical, being broadest near the base and tapering to a 
bluntly pointed apex. On March 14 it was noticed that these 
outgrowths were being devoured by slugs so some of the 
mummies were brought into the laboratory and placed on 
moist filter paper in a large Petri dish. Under these conditions 
development continued and by March 21, the upper portion 
of each outgrowth had elongated to form a stalk with a slightly 
swollen terminal knob which in some cases was already provided 
with a central pore. The pores gradually increased in size, the 
fructifications becoming cup- or funnel-shaped, and by March 29 
well-developed apothecia were present on two of the mummies, 
which bore ten and twelve sporophores respectively. Three 
days later the apothecia had become almost plane and were 
splitting at the margin. As the apothecia reached maturity 
it was found that, on removing the lid of the dish containing 
them, the spores were discharged in little visible clouds. Later 
several such discharges were distinctly seen on placing a mummy 
bearing ripe apothecia on black velvet exposed to sunlight. 
The number of sporophores growing from a mummy was 
variable; of those left in the open very few attained to their 
full development owing to the depredations of the slugs, but 
observations showed that the early stages (the rounded villose 
outgrowths referred to above) of some ten or more sporophores 
usually appeared on each mummied fruit. On one of the 
specimens brought indoors fifteen sporophores were counted. 
It is to be noted that the mummies were collected in the 
spring of 1920 before the trees came into flower; they had 
therefore passed the previous winter either on the tree or on 
the ground and, when the apothecia appeared, had been exposed 
in the open during two (at least) winters. That the medlar 
fruits do not produce apothecia until the second year after 
infection was observed by Schellenberg*; the same period is 
also required by other species of Sclerotinia, as shown by 
* Loc. cit. p. 189. 
