PROGEESS OF MICROSCOPICAL SCIENCE. 
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organism was discovered on horse-dung, and is nearly related to the 
curious Guttulina rosea of Cienkowsky, differing chiefly in the pre- 
sence of a common membrane in the organs of fructification. In 
watching the development of this organism, Professor Sorokine 
stumbled upon an interesting fact. Wishing to ascertain the eifects 
of a low temperature upon it, he placed some of it in the open air 
during the month of December, when the thermometer ranged between 
5*5° and 23° below zero Fahr. A few days afterwards he observed 
that some of the ^poranges contained portions of protoplasm and a 
distinct nucleus exactly in the centre of these fragments. Thus, 
although there are two kinds of organs of fructification produced on 
the surface of the dung, it is easy to distinguish them by the presence 
of a nucleus in the organs of later formations. Nevertheless, the 
writer was unable to determine which sexual part each of these two 
kinds played. They are quite distinct, and the result of their union 
is the formation of a cellule which may be termed an oosphere. 
Observations on the Protista. — ' Nature ' published recently a very 
interesting letter on this subject from a German correspondent. He 
states that Herr Cienkowsky, who several years ago made some 
exceedingly interesting communications on the low organisms known 
as Monads,* has recently contributed some additional information 
regarding them and allied organisms. f To the lowest order of plants 
belong the Myxomycetes, which, in the complete state, form proto- 
plasmic nets, named plasmodia. Cienkowsky found such plasmodia 
in fresh water, which fed themselves by suction of algae ; on passage 
into the resting stfite, they fell asunder into several cysts, and (what 
is deserving of special attention), by the release of small portions 
from their mass, produced amoeba, i. e. self-supporting individuals, 
which creep about by means of pseudopodia, and which have hitherto 
been regarded as independent animal organisms. As this phenomenon 
has also been observed in other plasmodia (Brefeld), it is not impro- 
bable that very many amoeba do not represent independent forms, but 
belong to the development cycle of other and plant-like forms. 
Ciliophrys infusionum, an organism which stands very near the animals 
named Actinophrys, is transformed, while under the covering glass, 
into a swarmer (swamspore), and when several individuals are con- 
nected, or one enters on the process of division, there arise as many 
s warmers as there were parts. Through this formation of swarmers 
there appears Heliozoa, which group belongs to the Actinophrys, closely 
related to Monads, or those lowest organisms which have been claimed 
both by zoologists and botanists as objects belonging to them. Among 
the Monads, Cienkowsky observes various encystments, divisions, and 
colony formations ; but the most remarkable of such processes is that 
in Dijploplirys stercorea, an extremely small cell-like organism with a 
yellow spot, and pseudopodia at two opposite ends of the body. These 
little bodies, observed in moist horse-dung, multiply by division, and 
form by union of pseudopodia, long strings in which separate indivi- 
duals can glide to and fro. In several of the organisms he examined, 
* ' Archiv. fiir Microscopische Anatomie,' i., 18G5. 
t Ibid., xii., 1875. 
