412 Miscellaneous. 
side of the body. With small Infusoria, such as Cyclidiwm glau- 
coma, the operation hardly lasts five or six minutes; but Parame- 
cium aurelia resists more than an hour before it is dissolved and 
disappears by being drawn into the current of the pseudopodia. The 
sarcode of the mass of the body isin constant motion. This motion 
does not take place regularly in the same direction, like the cyclosis in 
Paramecium aurelia. Itis quite as rapid as in that Infusorium; but 
splits up into currents with diverse and varying directions. This 
sarcode is hollowed out by numerous vacuoles of different volume 
and size, which are carried along by the currents, in which they are 
often seen to change their form and sometimes to amalgamate one 
with another. They always end by coming to the periphery of the 
body, where they contract in a similar manner to that of the so- 
called contractile vacuoles. JLeberkuehnia is therefore not, as has 
been stated, destitute of these organs of excretion. It is, on the 
contrary, perhaps more richly furnished with them than many 
other Protozoa. There is simply this difference, that the contrac- 
tile vacuoles are neither permanent nor localized in any region of 
the body, every part of which may serve as a basis for their for- 
mation. 
Lieberkuehnia, also contrary to what has been asserted, likewise 
possesses a great number of nuclec disseminated in the substance of the 
body ; these nuclei are spherical, and measure 0-004 millim. I have 
already described another Rhizopod* likewise combining in its 
structure the instability of the contractile vacuoles and the multi- 
plicity of nuclei. Further researches will undoubtedly increase the 
number of examples of this type of organization; and every thing 
leads me to believe that the Biomyxa vagans of Leidy + will, when 
more fully examined, show the same structure. The American 
naturalist has correctly recognized the numerous ephemeral vacuoles ; 
but the nuclei have escaped his notice. These types are further 
characterized by the great mobility of their sarcode, by the inces- 
sant variability of their general outlines, and by the large develop- 
ment of their pseudopodia. 
Lneberkuehnia increases by transverse division, which has been 
well described by Cienkowski. I will state, in addition to his ob- 
servations, that I have seen individuals divide, not only into two but 
into three. The body lengthened out into a long spindle, which, 
after the formation of two new peduncles bearing pseudopodia, 
became constricted at two points, and was thus divided into 
three nearly equal segments. One specimen, resulting from one of 
these divisions into three, developed, as soon as it was detached, a 
second peduncle bearing pseudopodia situated at the opposite 
extremity to the one it already possessed. It continued thus to 
live with two places of emission of largely expanded pseudopodia. 
I observed it in this state for more than a day without any further 
changes taking place than those slow ones in the form of the body 
above mentioned. In this, therefore, there was no preparation for a 
* See ‘Comptes Rendus,’ t. lxxxix. (1879), p. 252. 
} Freshwater Rhizopods of North America, p. 282. 
