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or less isodiametrical, whilst the walls are thin and, in accordance 
with the jodine-sulphuric-acid reaction, consist of cellulose. The 
inside of this envelope shows no separate differentiation; the paren- 
chyma extends unchanged until this inside. 
The structure of the inner apple accords in so far with that of 
the envelope, that it is also composed of a loose parenchyma of 
about isodiametrical cells, whose thin walls show cellulose reaction. 
The whole tissue is however filled up with a mycelium, the hyphae 
of which are in some places so numerous that in the glycerine- 
preparation the parenchyma cells can only be found with much 
trouble. The cellulose reaction, in which the hyphae are coloured 
yellow by jodine-kaliumjodine whilst the parenchyma cells grow 
dark blue, renders the latter distinctly visible. The mycelium is not 
everywhere equally compact. At the outside the hyphae are much more 
numerous than more inwardly; they form by their conglomeration at 
the surface a kind of layer which, on nearer view, is even visible to 
the naked eye. In all portions of the core, even in the seeds, the 
hyphae are to be found. In the interior of the endocarp the myce- 
lium is also very compact and there the hyphae are of a stronger 
structure than in the surrounding fruit-flesh. | 
As follows from the above description this apple not only deviates 
from the normal one by its monstrous structure, it moreover presents 
another curiosity: the presence of a fungus in the inner part, and 
the absence of it in the envelope. To my opinion this fact explains 
the monstrosity. I think that the fungus has grown at. first in the 
interior of the quite normal apple, and using some constituents of 
it as food, has more and more extended itself. The portion sucked 
out by the fungus has had a disposition for shrivelling and the 
tension between the healthy and the sick part of the fruit-flesh 
has finally become so strong that on the limit of both a splitting 
has originated, so that the apple was divided into two parts; an 
outer normal part and an inner one full of hyphae. The greater 
accumulation of hyphae at the surface of the inner portion of the 
apple has then probably taken place after the division, as the fungus 
will by preference develop there, where, in consequence of the splitt- 
ing, a space filled with air was present. With this explanation the 
following facts perfectly agree. The remains of the calyx and other 
flower-parts at the top of the inner apple fit precisely in the opening 
which exists between the dry fragments of the outer portion when 
these fragments are joined together. These remains have evidently 
formed one whole, so that there can be here no question of a flower 
within another. The fongitudinal section of a normal apple shows 
