1 DEc., 1898. ] QUEENSLAND AGRICULTURAL JOURNAL. 461 
In this memoir Dr. Brown states as follows :— 
On cutting across the fruit the staining of the tissue is at once noticed; the 
staining may be of a brown colour—of a lighter or darker hue--or it may be almost 
black and stretching from the scaly exterior to the ceutre. In the cavities beneath 
the bracts a whitish-greyish mould may often be noticed. The microscope reveals 
the cause of the condition noticeable. Sections of the discoloured patches were made 
with a freezing microtome and examined with a microscope. In some instances the 
cells (the ultimate constituents of the fruit) were seen full of spores of fungi, and in 
other instances hy pha interlacing as well as sporangia could be seen. The microscope 
revealed that the condition is a disease ca ised by the presence of a fungus belonging 
to the group Mucorini. Cultivations of the spores on slices from a healthy pine- 
apple resulted in the production of hyphe interlacing to form mycelia, and of 
sporangia full of spores. Zygospores were not seen. The fungus seems to be 
identical with Mucor racemosus. fungi belonging to the group Mucorini, when 
growing submerged in a fluid medium, result in the hyphs breaking up into spores. 
A pineapple being very succulent is practically a fluid medium; hence after the fungus 
has continued growing some time it breaks up into spores, and the sections show great 
spore formation. ‘The fungus is capable of exciting spirituous fermentation. The 
sugar present in the fruit is by its action broken up into alcohol and carbonic acid. 
Tn some instances in advanced cases on cutting across the fruit, a spirituous odour is. 
easily detected. The change in colour observed is due to the chemical changes 
wrought by the fungus in the protoplasm of the fruit. ; 
Pineapples under cultivation are, as a rule, perpetuated by planting the tops of 
ripe fruits, and also by planting the suckers. It is rare for pineapples to be raised 
from seeds, and, moreover, it is seldom that the seed of cultivated pineapples reaches 
maturity. 
Fungi may enter fruit in four ways—1. Fungus may enter the flower, and go on 
developing with the progressive growth of the flower to form the fruit. 2. Fungus 
may enter through the stomata (natural openings in the surface of the fruit). 3 
Fungus may penetrate through the firm membrane of epidermal cells. 4. Fungus may 
enter through a wounded surface. 
Having once become diseased with fungi, it is quite clear that the tops and 
suckers of such pines should not be used for the production of fresh fruit. 
In the course of this inquiry in no instance has a fungus that might be 
ascribed to the genus Mucor been found present in or upon the diseased and 
discoloured tissue, nor indeed any of the species possessed of internal spores 
ag are the members of the Mucorinex, nor again “ sporangia.” On the other 
hand, the brown tissue invariably contained the mycelia or spawn threads, from 
which arose the “ whitish-greyish mould” previously alluded to, and mentioned 
by Dr. Brown also, as occupying the cavities of the fruit. Again, inno instance 
was a special alcoholic fermentation remarked other than occurs in ordinary 
ripe pineapples, and such evidently eventuated under the usual conditions 
determining this event in their case, including the presence, numerical increase, 
and development of the alcoholic ferment-organism that occurs in this class of 
fruit. However, in the case of fruit affected by “core-rot,”’ fermentative changes 
are, as a rule, retarded. Further still, a pure cultivation of the organism 18 
incapable of producing alcoholic or indeed any other fermentative change. _ 
With regard to this special mould fungus, it is concluded that it is a species 
of Monilia, Persoon, allied to Monilia candida. It may be described as under:— 
Monilia, sp. (Plate LXX., Fig. © a-e). Hyphw procumbent, colourless, butcon- . 
taining granular matter, indistinctly septate, usually about °23 y* in diameter, with 
remote elongate branches arising singly at an angle less than a right angle. Spores 
elongate, parallel-sided, round at cach end, continuous, or very rarely 1-septate, 
colourless, containing unequal granules that in young spores tend to be segregated in 
two nuclei, averaging from 13-16 : long (but occasionally only from 5-11 p) Xx 2-35 
occurring terminally on sporophores of almost equal width with the hyphe, arising 
almost ata right angle therefrom, and from 16-27 long, although oveasionally only 9 pe 
On these supports the spores arise terminally with scarcely any constriction. They 
are rapidly formed, but are quickly caducous. Accordingly, twenty or more lying 
side by side may occur adjacent to a single sporophore. Germination 1s by sprouting 
almost always at one end of the spore; but the occurrence of septate spores points 
to possible rare development by fission also. 
One / is about equal to 355 inch. 
