8 THE AUSTRALIAN NATURALIST. 
Spumaria alba have spread to such an extent in meadow- 
land that the grass mown for hay has been considerably 
lowered in. value. [Th. Wulff in ‘‘Zeitschr. Pflanzenkr. 
xxiii, p. 2-5 (1908.)] These organisms are not regarded 
as parasitic in nature, and so far as can be ascertained, no 
active poison has been found to be present; but it is stated 
by Mr. George Massee (Diseases of Cultivated Plants, p. 
533, 1910) that instances are on record that‘horses and 
other animals have suffered, or even died, from the effects 
of having eaten the masses of spores adhering to grass, etc. 
It is suggested that in such cases the injury is caused by 
the irritating action of the spores on the mucous membrane. 
A disease which occurs in crops of cabbage and turnips, 
and known as ‘‘Club-root’’ or ‘‘Finger-and-toe Disease,”’ 
is caused by the species ‘‘Plasmodiophora’’ brassicae. An- 
other species, Spongospora subterranea (C. scabies of 
some authors), also causes a disease in potatoes known as 
‘“Gorky Scab.’’ These two species are somewhat different 
in their mode of life to the three previous mentioned species, 
as they do not form fruiting bodies like those that are 
found on rotten wood, etc., but live in the cells of the host- 
plant, so that in these two instances we may regard them 
as parasitic in nature. Although usually placed among 
Fungi, they show great affinities with the lower forms of 
the animal kingdom, especially with the Monadina group. 
Other organisms which show close relationship, and in 
former times called ‘‘slime-mould,’’ are those which cause 
malaria, which is said to live a part of its life in the body, 
of the mosquito, and then transmitted to man; and also 
another, which causes Texas fever of cattle. These latter 
groups of organisms receive greater attention from the zoo- 
logist than from the botanist. The chief distinction be- 
tween the Mycetoza and the fungi is that the vegetative 
body of the Mycetoza consists of naked protoplasm with- 
out a firm membrane, with no cellular mycelium, as in the 
true fungi. The spores germinate freely in water during 
‘warm weather, setting free a mass of plasma or swarm 
cells provided with a nucleus and vacuoles, which resembles 
amoeboid bodies. These soon acquire a flagellum at the 
anterior end, which aid in their movements in water. To 
a large extent the swarm-cells feed on bacteria, which are 
caught by pseudopodia projected from the posterior end 
of the body. The swarm-cells rapidly increase in number 
