306 DR. D. D. CUNNINGHAM ON MYCOIDEA PARASITICA, 
with solutions of iodine. When, however, the specimens are submerged, or when, 
during a continuance of wet weather, they are constantly saturated with moisture, the 
orange-colour is gradually replaced by a bright green, and the contents eventually come 
to resemble exactly those of the subepidermal disk-cells. 
The mature spores, if they may be so termed, vary somewhat in size; one of medium 
size, which was measured, was 0°0379 x 0°027 millim. Their contents appear at first as a 
uniform granular mass; but as time goes on a process of segmentation occurs in this, 
ultimately dividing it into from twelve to twenty-four, or even more, oval bodies; and 
whilst this process is being completed a rounded orifice forms in the thick wall of the 
spore (Pl. XLII. figs. 4, 5). This orifice is generally situated laterally, but occasionally 
occurs towards one or the other end of the spore. "When such ripe spores are wetted by 
the addition of water, by dew, or by rain, active swarming rapidly commences among the 
included oval bodies ; and after this motion has continued for a short time, they separate 
from one another, and emerge in rapid succession through the orifice in their mother 
cell as active zoospores. These are at first pear-shaped, measuring about 0:00825 x 0:0052 
millim., and are provided with a couple of long slender flagella, arising from the ante- 
rior pointed extremity (Pl. XLII. fig. 6). This extremity is almost colourless; but the 
rest of the body is of a reddish-orange colour by transmitted, and greenish by reflected 
light. They swim about actively for a short time, and then gradually become spherical 
and cease to move. The minute anatomy and subsequent history of these zoogonidia is 
identical with that of those developed in the sexual fructification, and will be further 
referred to in describing them. In some cases all the zoospores do not escape, one or 
two remaining behind in the mother cell and there undergoing various changes (Pl. 
XLII. fig. 5). Among the commonest of these is one in the course of which they gradually 
become circular green cells. The process of the formation of zoospores is at any time 
liable to be arrested by the addition of excessive moisture, which, as in the case of the 
filaments, causes the contents of the mother cells to become green, even after the process 
of division has advanced so far as to have caused the formation of distinct masses. Such 
green cellules do not usually appear to be capable of movement, but become gradually 
invested by distinct cell-walls, and remain within their mother cell until freed by acci- 
dental violence or by a process of gradual decay. "They are met with in great abundance 
during the height of the rains; but the age events i in their history have not been 
observed. 
After the escape of the zoospores from their mother ecliar $ the latter remain as sidity 
colourless appendages adherent to the capitellum. The filament, if it does not undergo 
further development, remains for some time erect, and then, falling over, lies prostrate 
on the surface of the pustule. The number of zoospores produced in this way is very - 
great during the continuance of moist weather, and amply suffices for the propagation 
of the parasite at such times. Towards the close of the rainy season, however, the 
formation of filaments gradually diminishes, and, as the cold and dry season advances, 
ultimately ceases altogether. The patches of the parasite are now entirely subepidermal, 
and hardly extend at all peripherally. They are of a bright orange colour; and many of ` 3 
them dry up entirely and die off. Were there no special Mm c securing the pre- E 
