354 
Essed . — The Panama Disease. II. 
another case the spore-initials are seen to prepare themselves a way through 
the hyphal walls, so that at last they are found densely massed on the surface 
of the hyphae, more or less deeply embedded (see PL XXIX, Fig. i). During 
the migration of the spores, the hyphae swell to twice or thrice their original 
thickness and then harden into pegmatia. In a third case the hyphae 
become somewhat toruloid, some parts being largely distended. Here and 
there spore-initials are seen lying within or embedded in the cell-walls. 
Before pegmatium-formation sets in, the hyphae assume a smoky hue, the 
lumina become very much narrowed, and the outlines quaintly altered. 
Then the dissolution of the cell-walls ensues, giving rise to a gelatinous 
mass, out of which the pegmatia arise as yellowish, greenish, or dark- 
brown bodies. In a fourth case, gelatinous opaque masses exude through 
invisible openings in the cell-walls (see Fig. 2 , a) ; these masses consist of 
the entire or partial contents of large hyphal cells, which arose from 
different adjacent cells by the absorption of the septa ; they harden in the 
end into pegmatia, of which the mycoporomatic coat is formed out of the 
gelatinous substance, and not from the hyphal walls. This mycoporoma 
may be compared with the hypothallus of some Myxogasteres. In a fifth 
case, terminal or interstitial cells of special hyphae emit little knob-like 
outgrowths, which gradually assume a cup shape. They are at first trans- 
parent, but gradually a thick mycoporomatic coat is formed, enclosing 
a glairy gelatinous inner part ; this is best seen when viewed through the 
upper surface, where the coat seems to be thinner and somewhat trans- 
lucent. These bodies may arise in large numbers beside each other, and 
may not or do closely abut on each other ; complete fusion seems to be 
rare (see Fig. 2, a). They may be compared to the chlamydosporangia of 
Sorosporium and some other Ustilagineae, in which, however, the wall is 
formed out of infertile hyphae instead of the walls of fertile hyphae. In 
some cases, when originating on the apices of hyphae, they assume a 
globular shape ; the wall may then be a thin mycoporomatic coat, and the 
bodies may be fertile or not ; in the latter case large spore-like bodies, 
which are empty and therefore sterile, are seen to form within. Finally the 
bulk of the mycelium in the decaying plant may turn at the end of its vege- 
tative development to the resting condition, enclosing the tissue-remnants 
within pegmatia. When plenty of moisture is present the pegmatia give 
rise to chlamydospores in huge numbers, which are at first polyhedric lumps, 
but gradually assume their definite shape. The exosporium appears to be 
formed out of the mycoporoma ; at any rate it always has the same colour, 
a reason why the chlamydospores arising from the pegmatia in the plant 
tissues show a great variety of colour, which may be some shade between 
yellow and dark brown. When a limited quantity of moisture is present 
the pegmatia at once germinate into new mycelia or they may give rise to 
fruit bodies, as was shown in my first paper. 
