![](./pubData/source/images/pages/page18.jpg)
protuberances into which the whole of the protoplasm passes,
leaving behind the remainder of its pellicle attached to the
substratum, and known as the liypotJiallus. When these
protuberances, which may he sessile or stipitate, are symmetrical
and individually distinct, they are called sporangia; when
sporangia are irregular in form, usually veinlike and creeping,
the term plasmodiocarp is used ; finally, when the sporangia are
densely aggregated, so that their individuality disappears to a
greater or less extent, an aethlium is produced. The three
conditions are connected by intermediate links. Aethalia are
most frequently sessile on a broad base, as in Tubulina cylindrica
and Fnteridium olivaceum, but stipitate aethalia are not uncommon,
especially in the Triehiaceae, where the transition from
typical sporangia to aethalioid forms in many species is very
instructive.
As previously stated, the late Professor De Bary was the
first to show, by his admirable researches on the morphology
and physiology of the Myxogastres, that the systematic arrangement
then in vogue was no longer tenable, owing to the fact
that it was founded on analogies rather than affinities; and
although at the present day it must be admitted that, within
the group, affinities are far from being settled, yet, the appearance
of Dr. Rostafinski’s Monograph based on De Eary’s researches,
gave a fresh impetus to the study, and showed in a
masterly manner, that well-marked morphological features, far
beyond the ken of pocket-lens revelation, could be utilized in
connection with the systematic disposition of the members of
the group. Among the essentials still lacking for an approximately
correct classification are more especially—amount of
variability, as also its direction in the various sections ; the
relative value of such structures as the columella, capillitium,
sporangial, aethalioid and plasmodiocarp forms; the presence or
absence of lime, as also its amorphous and crystalline condition
as presented in different sections ; and finally, what is undoubtedly
of primary importance, a complete knowledge of the life-
history of at least the representative species of each section ; and
although complete life-histories might not in all cases be
possible, yet in so difficult a subject, the modus operandi alone
would enable others to follow along the same lines. In the
present state of knowledge, the markings usually present on the
epispore appear to be constant within narrow limits, are often
very characteristic, and of value as one factor in the discrimination
of what we at present consider to be species, nevertheless I
wish to express the strongest dissent to species founded on spore
characters alone, or indeed on any one character. Rostafinski
was the first to use spore characters in a specific sense. I t is
important to bear in mind, that the apparent nature of spore
ornamentation depends entirely on the amount of magnifying
power used; the complex epispore of Trichia afflnis appears
only as a confused series of minute irregular projections under a
quarter-inch objective, consequently there is no absolute character
in the spore unless a uniform magnifying power is agreed
upon. The objective used in determining the nature of the
epispore as described in the present work is a oil immersion,
which gives a magnifying power of 1200 diameters. So far as
the synonymy is concerned, I can only repeat in substance what
I have written on a previous occasion in connection with the
same subject. I have not included the synonymy further back
than Rostafinski’s Monograph, unless justified by the presence
of type or authentic specimens. Rostafinski has given synonyms
dating from the time of Micheli (1729), but on referring
to the earlier descriptions, I realize my weakness, in not being
able to reconcile the wonderfully brief descriptions, and equally
crude drawings, with modern species, which in many instances
require a magnifying power of 1000 diameters for their determination,
hence I wish to be clearly understood that the
synonyms headed “ Rostafinski’s Synonyms,” are copied from
Rostafinski’s Monograph without any attempt at corroboration.
I feel certain that nearly one-third of Rostafinski’s work would
not have been sacrificed to synonyms unless they mean something
more than I have been able to discover, hence I have not
felt justified in ignoring them altogether.