470 THIRD PART.—BACTERIA OR SCHIZOMYCETES. 
become aggregated in the water into slimy masses a foot in depth. The gelatinous 
matter is at first colourless, but may assume a colour varying from brick-red to dark 
brown by admixture of hydrated oxide of iron. When grown in bog-water the cocci 
develope into rods or filaments (4) of unequal thickness, which at a certain age become 
invested with a continuous thin but firm gelatinous sheath with the same admixture of 
iron as is found in the 
jelly of the zoogloea-forms. 
The single rod-like cells 
within their sheaths pass 
by repeated transverse bi- 
partitions into the form of 





& nearly isodiametric mem- 
e 9 bers, which then round 
a themselves off. The mem- 
| bers in the thicker filaments 
ei =| often assume a flat disk-like 
A Fl on |} shape, and then divide into 
N N ’n = | FJ 2-4 small cells by walls 
\ SQ | & i parallel to the longitudinal 
a mA W lH axis of the filament. Both 
3 \, H ® = 7 °Ps these cells and the rounded 
f \ A ® = fa) members of the slenderer 
9 f Mook 8 H filaments ultimately escape 
AA U 2 = j : q 
\a ‘| \ <, 4 m j in the form of cocci from 
INN BO ‚dei H fp the sheath, being set free 
re; H f partly by the swelling of 
We the sheath along its whole 
length, partly by its rupture 
at the apex (7). In the 
latter case some of the cocci 
slip of themselves out of the 
opening in the sheath, while 
others are passively thrust 
out of it by the growth in 
length of the other parts 
which remain in the sheath. 
The cocci may, though they 
FIG. 196, Crenothrix Kühniana. a—¢cceci 


orspores. e—ecoecidiyjding. /cocci rarely do, become motile, 
collected into a group and d ‘h ya ib "zoo- a : 
gloea’),the contour dark. % agroup of cocci developing into filaments, —rfilaments and pass again out of this 
of various forms and stoutness hed below to a sub ; m—r show the for- 

mation of the common sheath round the single members; ¢ and nm separating above 
state into the resting zoo- 
into members; » with the upper ly broader and com- 
ively shorter, the upp bers having d by longitudinal divisions 
a vin gloea-form; they also de- 
into round spores (‘cacci’), which have escaped at the upperjend from the sheath. h 
£ cocci-zoogloeae. After Zopf. gnatural size, the rest magn. 600 times. velope once more into rods 
and filaments in the manner 
which has already been described. In addition to these forms curved spirilla-like 
forms are also found, which may also break up into pieces, but without passing, as 
far as has been at present observed, into the motile state. 



