he _Hymenomycetes_, the
prevailing type of reproductive organs consisted of quaternary
spores borne on spicules; so in _Gasteromycetes_, the prevailing
type, in so far as it is yet known, is very similar, in some cases
nearly identical, consisting of a definite number of minute spores
borne on spicules seated on basidia. In a very large number of
genera, the minute structure and development of the fructification
(beyond the mature spores) is almost unknown, but from analogy it
may be concluded that a method prevails in a large group like the
_Myxogastres_ which does not differ in essential particulars from that
which is known to exist in other groups. The difficulties in the way
of studying the development of the spores in this are far greater
than in the previous order.

[Illustration: FIG. 10.--_a._ Threads of _Trichia_. _b._ Portion further
magnified, with spores. _c._ Portion of spinulose thread.]

MYXOGASTRES.--At one time that celebrated mycologist, Professor De
Bary, seemed disposed to exclude this group from the vegetable kingdom
altogether, and relegate them to a companionship with amoeboid forms.
But in more recent works he seems to have reconsidered, and almost, if
not entirely, abandoned, that disposition. These fungi, mostly minute,
are characterized in their early stages by their gelatinous nature.
The substance of which they are then composed bears considerable
resemblance to sarcode, and, did they never change from this, there
might be some excuse for doubting as to their vegetable nature; but as
the species proceed towards maturity they lose their mucilaginous
texture, and become a mass of spores, intermixed with threads,
surrounded by a cellular peridium. Take, for instance, the genus
_Trichia_, and we have in the matured specimens a somewhat globose
peridium, not larger than a mustard seed, and sometimes nearly of the
same colour; this ultimately ruptures and exposes a mass of minute
yellow spherical spores, intermixed with threads of the same
colour.[V] These threads, when highly magnified, exhibit in themselves
a spiral arrangement, which has been the basis of some controversy,
and in some species these threads are externally spinulose. The chief
controversy on these threads has been whether the spiral markings are
external or internal, whether caused by twisting of the thread or by
the presence of an external or internal fibre. The spiral appearance
has never been called in question, only the str