272 Chronicles of Science. | April, 
cetes, Stein and others have shown that a large number of Infu- 
soria, when first they emerge from the parent Infusor—by the 
breaking-up of whose nucleus or ovary they have been formed— 
assume the Acineta form, exhibiting those peculiar sucker-like 
pseudopodia which are characteristic of the remarkable Aczneta. 
Now it is freely admitted that there are Amcbx and Acinet# which 
are not mere transient stages of an existence; but is it so with 
Monas? Professor H. James Clark, of Philadelphia, has recently 
done much to solve this question. He has used very high powers 
of the microscope, and has studied the Monas forms of ponds and 
streams. He describes and figures, in a very careful and satis- 
factory manner, a mouth, nucleus, and contractile vesicle in what 
he calls the Monas termo of Ehrenberg ; and he describes, in addi- 
tion, a series of forms exhibiting two, six, or more monads, united 
by stalks, and lymg within cup-like sheaths. These forms he 
maintains lead ultimately to the ciliated Sponges. Just as we may 
regard the ordinary “ sponge particles” as Amcebe, and the sponge 
therefore as an aggregation of Amcebz with a horny and siliceous 
skeleton, so in the case of Leucosilenia and others, Professor James 
Clark thinks we must consider the sponge-particle as a flagellate 
Monad—a more or less complete gradation leading from the simple 
Monas, through the compound forms with their cups and stalks, up 
to the ciliated Sponge. 
A New Group of Protozoa.—Professor Cienkowski has discovered 
a new organism, which like some others of simplest structure, holds 
a doubtful place between plants and animals. These creatures, to 
which he gives the name Labyrinthulea, were found encrusting the 
weed-grown posts in the harbour of Odessa. They are of micro- 
scopic dimensions and form a network of thin, reticulate, colourless 
filaments, on which fusiform bodies circulate very slowly in various 
directions. In various parts are embedded globular masses, from 
and into which the filaments appear to arise and to be inserted. 
The reticular arrangement is sometimes supplanted by an arborescent 
form. The network as well as the arborescent ramifications spring 
from a central mass, which is sometimes as big as a pin’s-head. 
The substance of the filaments is solid and non-contractile, hence 
they are not like the pseudopodia of Rhizopods. The fusiform 
corpuscles are nucleated and nucleolated, and appear to consist of a 
protoplasmic substance. The cause of their movement is very 
obscure. The relation of these organisms to other groups of 
Protozoa or Protophyta is very difficult to pronounce upon, since 
they seem to present but very little definite relationship with any 
one more than another. The corpuscles multiply by division, and 
occasionally the whole Labyrinthula becomes encysted, but there 
is nothing known of the reproductive process which will help to 
determine their affinities. They must be considered as a new group 
of Protozoa. 
