460 QUEENSLAND AGRICULTURAL JOURNAL. [1 Dec., 1898. 
On cutting the affected pineapple across, it is to be observed that the 
central axis presents a quite healthy appearance. The same remark applies 
to the general tissue beyond the immediately affected parts. But the portion 
underlying the externally altered surface is already dark-brown and decayed, 
the area so changed corresponding in extent to that of it. This discoloured area 
may already form a patch continuous with the outside surface of the pine exter- 
nally, and pass inwards to a varying depth of from 2-inch to }-inch. The inner 
border of this area is very clearly defined, though exceedingly irregular. In 
addition to this, there may occur without any corresponding surface area of 
decay, and well within the margin, isolated patches of discoloured tissue that 
vary greatly in size but agree in being restricted to individual sections. So 
also on cutting across a fruit that has not as yet developed any external 
indications of the disease, or but obscure ones only, similar islets of affected 
tissue are revealed, from which it may be concluded that the malady com- 
mences independently, but not simultaneously, in separate fruitlets. (Plate 
LXVIII.,B.) 
__ On dividing lengthwise a series of these fruitlets, so as to display the 
existence of the disease in its successive stages, it will be found that the 
features presented do not quite correspond to those described as occurring in 
the Prickly Queen variety of pineapple. Thus the malady in the variety under 
notice commences with the formation of one or two small patches in the tissue, 
immediately beneath that portion of the base of the cavity or chamber that 
occuts below the level at which the stamens are inserted, and, though it 
ultimately invariably extends downwards into the ovary proper of the fruitlet, 
it tends rather in the first instance to invade the tissue occurring laterally to 
its point or points of origin, and to pass upwards into the fleshy sepals (which 
never happens in the case of the Prickly Queen), with the result that the 
diseased area becomes ultimately at length continuous with the outer surface of 
the fruit. (Plate LXX.,B d.) It is considered, however, that these distinctive 
features are in accord with the marked structural differe nees, in matters of detail, 
that exist between the fruits and fruitlets of the two varieties mentioned, and 
which need not be now detailed. The further fact that the special fungus asso- 
ciated with the diseased condition is not identical with the one met with in this 
relation in the case of the Prickly Queen variety, but is the Penicillium that is 
derived from the dead and dried-up essential organs of the flowers, in which 
position it occurs in the fruitlet cavities of both varieties alike, is not, however, so 
significant as it might at first appear, seeing that they are both saprophytic 
fungi, and therefore secondary in their relation to the disease; whilst at the 
same time also the fact that they are different, and have their separate physio- 
logical characteristics, will in a measure account for the difference in symptoms 
that has been described. 
CAUSE. 
Causes Hitherto Assigned.—(1) Prior to this disease having been made the 
object of special inquiry on the part of the present writer, it had been regarded 
by him—as already reported—as being “a form of natural decay affecting 
fruit subjected to conditions inimical to the progress of normal ripening” ; 
the fact that it had been “encountered for the most part in pineapples 
produced in the ‘ off season’—i.c., during the winter and early spring months— 
-and also in such fruit as had been (apparently) prematurely harvested,” being 
suggestive of such explanation. This theory as to its origin has, moreover, since 
proved to be untenable. (2) From an examination of affected examples of the 
Prickly Queen pineapple alone, especially having in view the fact that a 
special fungus is invariably present in connection with the portions of 
of discoloured tissue observable, it might be again inferred that the invasion of 
healthy tissue by this organism was the primary cause of the disease. ‘This 
is the explanation as to its origin adopted Dr. A. A. Brown, M.B., Ch.B., 
of the Stock Branch of the Agricultural Department of Victoria, as would 
appear from his able report on “ Disease in Pineapple,” written in 1896, of 
which a copy in manuseript has been obligingly placed at the disposal of the 
writer. 
