THE MYXOMYCETES OR MYCETOZOA ; ANIMALS OR PLANTS ? 99 
that formula of organization distinctive of the lowest or Pro- 
tozoic section of the animal kingdom. Of the two residual 
groups, that of the Diatomeao as assuredly belongs to the vege- 
table series ; one only being finally left, of which it may be said 
that opinions are substantially divided as to their animal or 
vegetable affinities. It is with this single section, No. 7, or 
that of the Myxomycetes, that this article purposes to deal. 
The Myxomycetes, Myxogastres, or Mycetozoa, as they 
have been variously designated, have up to a very recent date 
remained undisturbed within the precincts of the vegetable 
kingdom, being accepted on all hands as constituting a subor- 
dinate, though somewhat abnormal group of the Gastero- 
myeetous Fungi. The diagnosis of the order, as given in M. 
J. Berkeley’s Introduction to Cryptogamic Botany , 1857, and repro- 
duced in other English text-books of Mycology, runs as 
follows : — 
‘ Whole plant at first gelatinous. Mycelium often vein-like , 
forming reticulated or anastomosing strata, but sometimes diffuse, 
giving rise to sessile or stipitate, free or confluent peridia , consisting 
of one or more membranes, enclosing, ichen mature, a dry mass of 
threads or plates, and spores; at length often bursting. Threads of 
various structure, sometimes containing one or more spirals .’ 
Mr. Berkeley further proceeds to say (l.c. p. 336), — 4 This is, 
perhaps, one of the most remarkable groups of Fungi, and at 
present one on which we have least information. In their early 
stage they consist of a pulpy or cream-like mass, collected in 
distinct globules, or creeping over its matrix in the form of 
branched anastomosing veins. In this stage the tissues are so 
delicate that they exhibit no structure, and if hardened with 
alcohol give no further information. From their great fragility 
when fully grown, and the free dispersion of their dust-like 
spores, they are with difficulty preserved in an herbarium. 
But no Fungi afford more elegance of form or singularity of 
structure according to the nature of the peridium, the flocci, and 
the disposition of the spores, which are their three main ele- 
ments. The beauty of form of their peridia is often combined 
with exquisite colouring, which is sometimes brilliantly metallic, 
exhibiting tints of steel, gold, copper, or silver, most nearly 
resembling in this respect very thin membranes met with in 
the animal kingdom, such as those of the eggs of certain moths. 
One form, JEthalium septicum, is the pest of hothouses, while a 
species of Licea, L. per rep tans, sometimes increases with such 
rapidity in cucumber and melon-frames, as to seriously inter- 
fere with the culture of these fruits. One marked peculiarity of 
the Myxomycetes is represented by their indifference as to 
the matrix upon which they grow. The same species may 
occur on plants of the most distant natural affinities, and on 
