178 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 
number of constituent amcebz from 18u long by 8u broad to 48u long by 23 broad. 
In fusing the amcebe adhere closely to one another, finally after some time fusing 
into one mass, which can then undergo further movements. Nuclei (pl. 4, fig. 8 N) 
of plasmode vesicular, 2 to 3 according to the number of constituent amebe. 
Union or fusion of the nuclei not directly observed; regarded, however, as very 
probable, as frequently pretty large plasmodes of 22 and 184 (doubtless 
[Page 19] formed by fusion of 2 or 3 amb) were seen containing only 1 large, 
vesicular nucleus (pl. 5, fig. 2N). Besides, plasmodes seen to originate 
by fusion of 3 amcebe and to contain nuclei, showed on the next day only 1 large 
nucleus. 
Contractile vacuole not demonstrable with certainty in fusion plasmodes; its 
presence, however, not regarded as impossible; the plasma, on the contrary, con- 
tains so many vacuoles as to appear vacuolate or frothy. Motion of plasmodes 
rather slow. Plasma in the next 24 hours undergoing a change; the frothy, vacuo- 
late structure changing to a finely granular condition, the vacuoles vanishing. 
Nucleus, also, no longer visible; probably transformed by division into several 
globular strongly refringent bodies (pl. 5, fig. 3 N), though this was not directly 
observed. Motion of plasmode in this stage quite slow, ceasing entirely after some 
time; encystment following in 1 or 2 days. 
2. Encystment.—The encystment of simple small amebze and the alterations in 
their body plasma is first described; afterward the process with the fusion plas- 
modes. Withthesmall amcebe encystment begins when they have attained a certain 
size. They gradually draw in their lobulate pseudopodia and acquire an irregular, 
more or less oval or pyriform shape. Locomotion still takes place, though very 
slowly, small ragged pseudopodia being still emitted. After about 1 hour this move- 
ment also ceases and the amceba revolves slowly, gradually rounding itself off and 
assuming with a state of rest a nearly globular form. After about 10 hours it has 
transformed itself into a proper cyst (pl. 4, fig. 3) about 10m in diameter, 
[Page 20] consisting of a plainly bordered, extremely thin membrane and finely 
granular contents, in which individual, small, strongly refringent gran- 
ules, a vesicular nucleus (N), and a contractile vacuole (c. v.), which now pulsates 
markedly more slowly, are perceptible. 
After about 24 hours (pl. 4, fig. 4) the membrane appears markedly thicker, double 
contoured, and the strongly refringent granules have increased in number. The 
nucleus no longer appears vesicalar, but homogeneous and rather strongly refringent. 
Contractile vacuole still always visible, although now pulsating extremely slowly 
(about once in 5 minutes). 
After another 24 hours (pl.4, fig.5)the protoplasm appears strongly brilliant, the 
contractile vacuole has vanished, and the nucleus is not perceptible. In their places 
are observed several round, strongly refringent structures (probably proceeding 
from division of the nucleus), differentiated from the other cyst-plasma granules 
already mentioned, by their more considerable size and their affinity for stains. 
Though the falling to pieces of the nucleus was not directly observed, the granules 
may with tolerable safety be admitted to have originated through nuclear division. 
Schewiakoff thinks that first the nucleus divides, and about 10 hours later the spores 
(pl. 4, fig. 6) are formed, since around every nucleus a portion of the protoplasm 
delimits itself from the remainder. 
Encystment of plasmodes occurs in the same way. Locomotion becomes con- 
tinually slower until finally it is extinguished. The plasmode then rounds itself 
off, acquires a somewhat elongate oval form, which, as also the size, varies 
greatly. It then secretes a thin membrane, which envelops it closely on every side 
(pl. 5, fig. 4). 
[Page 21] In 1 to 2 days the membrane becomes markedly thicker, then appearing 
homogeneous, strongly refringent and double contoured. During the 
next day spore formation begins. 
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