i 
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Special Morphology and Classification. 259 
large swarmspores provided with two cilia, which are formed in in- 
definite numbers in special cells. No process of impregnation has been 
at present detected in them. 
_ The FLORIDE# are red or violet- epfoured seaweeds, the green 
colour of their chlorophyll-grains being concealed by a red;;pigment 
which can be extracted by cold fresh water. They are propagated 
[sexually] by means of oospores formed in capsular fruit-like cells, the 
cystocarps (see Fig. 386, p. 253), and [asexually] by éetraspores (Fig. 
382, p. 251), produced in fours in special cells. 
The CEDOGONIE, to which allusion has already been made, differ 
so greatly from other Algze in the processes which accompany their 
reproduction, that they cannot be included in any of the classes already 
named, but form a distinct one by themselves (see Fig. 385, p. 252). 
The SCHIZOMYCETES form a kind of supplementary class ; a group 
of small organisms so near the extreme boundary of visibility that the 
separate individuals appear only as minute dots or rods even under the 
most powerful enlargement. All these organisms are characterised by - 
the ease with which they break up into their separate cells as soon as 
they come into contact with the atmsophere, from which circumstance 
they have received their name. ~They include the forms known as 
Termo, Bacterium, Vibrio, Spirillum, Leptothrix, &c. (Fig. 391). 
There are, however, apparently dis- 
tinct genera and species belonging l Og on, > 
to this class, which exist on par- u bey Ya? oe 
ticular nitrogenous compounds, and ie yi, ee } 
which are probably the: cause of Cee 
different modes of decomposition of \ rane 
their substratum. They multiply 
by transverse division into two simi- 
lar daughter-cells, which either be- pyc. 397.1. Bacteria: IL. Vibriones 
come isolated at once, or remain III. chain of Leftothrix; IV. gela- 
: 3 tinous colony of Zooglea choleree ; Vv. 
connected for a considerable time, S4oronema gracile. (x 1000.) 
and thus develope filiform or tabular | 
colonies of cells. They usually grow in water, splitting up the nitro- 
genous compounds which are contained in it into ammonia which sup- 
plies them with nutriment, and other substances which arise as second- 
ary products of decomposition. Such decompositions of nitrogenous 
substances are known as futrefaction, and the Bacteria are the sole 
causes of it, while the moulds and infusoria commonly found in putre- 
fying substances must be considered only as accompaniments of putre- 
faction. Solid nitrogenous compounds which are insoluble in water 
are rendered fluid by the agency.of Bacteria. These bodies usually 
5 2 
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