14 



germinated were difficult to measure properly, especially in width, 

 it being impossible to allow for the amount of collapse due to ger- 

 mination. 



It should also be remarked that the growth was very slow and not 

 very decisive; in fact, I felt convinced for a long time that no 

 Gloeosporium was present, and that the disease was an accidental 

 growth of Penicillium, and nothing else. An earlier microscopic 

 examination would have been better. 



I succeeded in infecting another pear with spores of this fungus. 



Ripe-rot fungus on Passion-fruit. (Fig. 32.) 



On the 22nd March, 1901, I received some passion-fruit suffering 

 from a ripe rot, caused by a species of Gloeosporium not distinguish- 

 able in form from Gloeosporium fructigenum. The diseased spots also 

 showed the concentric markings so characteristic of the ripe rot of 



Fig. 32. Spores of the Gloeosporium, found growing naturally 

 on the fruit of the passion-vine. a, freshly removed 

 spores; b, germinating spores, one of which has already 

 produced a secondary spore. 



spa 

 X400 T& 



the apple and other fruits, presenting more or less of a buff colour 

 with rings of a darker shade. The infested areas were usually of a 

 circular shape, and sunken. As the disease progressed the spots 

 collapsed, and the shell of the fruit became dry and brittle. The 

 spore-producing pustules were less numerous than is usual on other 

 fruits, but were of the usual size. The spores are shown in Fig. 32. 



The diseased spots were at first small and green, but at this stage 

 were not sunken as they, were at a later stage. As the disease 

 progressed the spots enlarged, and, while gradually sinking inward, 

 assumed the above-mentioned buff colour with concentric markings. 



The disease was said to be causing a great deal of damage. 



On being cultivated, the spores germinated in precisely the same 

 manner as those of the ripe rot of the apple, producing secondary 

 spores in about fifteen hours. These are shown in the illustration 

 referred to above. Prior to the germination, or pari passu, the 

 spores became two-celled. Perhaps the prominence of the " nucleus/' 

 as ordinarily seen on removal of a spore from its pustule, is due to 

 the condition in which the spore then exists a condition preliminary 

 to division. 



The secondary spores are smaller than the primary, and are darker 

 in colour, as well as more coarsely granular. In form they are some- 

 what spherical. (See Fig. 32, b.) 



Apples, pears, grapes, guavas, peaches, bananas, and date-plums 

 were inoculated from the spores of the ripe rot of the passion-fruit on 

 March 23rd, 1901. A few days later pineapples, tomatoes, quinces, and 

 peppers were inoculated. 



None of these appeared to take except the tomatoes, which on 

 April 9th showed three pustules on one small spot, as yet unripe, and 

 not bearing spores. These appeared to be true G-loeosporium 



