nish, finely verruculose, dotted
wall.

[Illustration: FIG. 102.--_a._ _Aspergillus glaucus_; _b._ conidia; _c._
germinating conidium; _d._ conceptacle of _Eurotium_; _e._ ascus.]

The same mycelium which forms the pedicel for the conidia when it is
near the end of its development, forms by normal vegetation a second
kind of fructification. It begins as delicate thin little branches,
which are not to be distinguished by the naked eye, and which mostly
in four or six turns, after a quickly terminated growth, wind their
ends like a corkscrew. (Fig. 102.) The sinuations decrease in width
more and more, till they at last reach close to one another, and the
whole end changes from the form of a corkscrew into that of a hollow
screw. In and on that screw-like body, a change of a complicated kind
takes place, which is a productive process. In consequence of this,
from the screw body a globose receptacle is formed, consisting of a
thin wall of delicate cells, and a closely entwined row of cells
surrounded by this dense mass (_d_). By the enlargement of all these
parts the round body grows so much, that by the time it is ripe it is
visible to the naked eye. The outer surface of the wall assumes a
compactness and a bright yellow colour; the greater part of the cells
of the inner mass become asci for the formation of sporidia, while
they free themselves from the reciprocal union, take a broad oval
form, and each one produces within its inner space eight sporidia
(_e_). These soon entirely fill the ascus. When they are quite ripe,
the wall of the conceptacle becomes brittle, and from irregular
fissures, arising easily from contact, the colourless round sporidia
are liberated.

The pedicels of both kinds of fruit are formed from the same mycelium
in the order just described. If we examine attentively, we can often
see both springing up close to one another from the same filament of a
mycelium. This is not very easy in the close interlacing of the stalks
of a mass of fungi in consequence of their delicacy and fragility.
Before their connection was known, the conceptacles and the conidia
pedicels were considered as organs of two very different species of
fungi. The conceptacles were called _Eurotium herbariorum_, and the
conidia bearers were called _Aspergillus glaucus_.

Allied to _Eurotium_ is the group of _Erysiphei_, in which
well-authenticated polymorphy prevails. These fungi are developed
on the green parts of growing plants