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apical portion usually more or less globose ; the membrane of
the plasmodium is continued upwards to form the wall of the
stem and sporangium, the protoplasm of the plasmodium passes
into the newly formed sporangia, undergoes differentiation
frequently resulting in the separation of lime which may form a
crust outside the sporangial wall ; spores are differentiated, and
generally a surplus portion of the protoplasm takes the form of
a more or less complicated network mixed with the spores, and
homologous with the strands described as being present in the
sporangium of Mrccor, inasmuch as both structures are made
from a substance separated from protoplasm during spore-
formation ; finally, the cell-wall of the spores of the Myxomycètes
agrees with that of the spores of fungi in giving a celhilose
reaction when young ; as differentiation of the wall proceeds, in
common with the spores of fungi, mosses, and ferns, the
cellulose reaction is no longer obtained, except perhaps in the
inner layers. The above comparison between Mucor and the
Myxomycètes is not introduced with the view of showing close
homologies, but to draw attention to what I consider may, at
least, he accepted as a series of analogies, which, accepting De
Bary’s opinion, would, in the present connection, indicate
affinities, as we find it formulated that in searching for affinities,
“ we find it impossible to establish any strict homologies, and
we are limited to the observation of resemblances in form,
structure, and mode of life.”
I regret to say that I am not sufficiently familiar with the
lower forms of animal life to indicate any group presenting an
equal number of analogous points with the Myxomycètes, a,s have
been described above in the fungi belonging to the Mucorini,
otherwise I should be too pleased to do so ; it is not my desire
to endeavour to force the Myxogastres into filling a preconceived
gap in the vegetable kingdom, but simply to analyze the reasons
advanced in favour of their exclusion from the plant world;
personally it is not a matter of prime importance whether it be
eventually shown that I have been a botanist or a zoologist.
I t is admitted by De Bary that the wall or membrane of
plasmodia, the oell-walls of spores, and various other structures
belonging to different orders of the Myxogastres, give a characteristic
cellulose reaction, and more extended experiments
were only required to show that the presence of cellulose
during some or other phase of development is general in the
3Iyxomycetes ; cellulose as a protective substance cannot be said
to be so generally present as in phanerogams, neither is it so
genez'al in the fungi, hence the term fungus-cellulose. In the
Acrasieae the stipes in many species consists of one or more
rows of superposed cells having the walls composed of cellulose.
The presence of cellulose, according to De Bary, is the only
character showing that the Myxogastres are in touch with the
vegetable kingdom.—“ The Mycetozoa show only a slight agreement,
either in the general course of their development or in
the characteristic features of its separate stages, with organisms
that are of undoubted vegetable origin ; whether they bo fungi
or plants other than fungi ; the agreement, with the exception
of a few cases in which cellulose makes its appearance, is
confined to phenomena which are common to all organized
bodies.” ’
I cannot reconcile the above sweeping statement with the
two following, first—in connection with affinities, “ w'eare limited
to the observation of resemblances in form, structure, and mode
of life ” ; second, “ the resemblance of the Mycetozoa to the
Fungáis due partly to their mode of life and nutrition, partly
to the close agreement in structure and biological characters
between their organs of reproduction and the spores of Fungi.”
One more point given by De Bary in support of the animal
nature of the Myxogastres requires to be noticed. “ I t is obvious
moreover according to our present knowledge that the Mycetozoa
are the superior terminal member or the two terminal members
of a series of forms or developments which commence elsewhere.
The most highly differentiated sections of the group, tlie
Calcareae, Trichiae, Lycogala, and others, give evidence of no
close affinity with any more highly differentiated group ; in other
words, like the Gastromyeetes with which they were classed by
earlier botanists, they do not connect with any group above
’ Tom. cit. p. 444.