612 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
pliora. He suggests that they might he called Silicoflagellata, and 
defines them as follows “ Flagellate-like organisms, with a radially 
symmetrical shell composed of hollow siliceous elements, with an unen- 
sheathed body and a long thin flagellum, with a nucleus (observed only 
in Distephamis speculum ) vesicular in form and consisting of a central 
nucleolus and a vacuolar cortex.” The shells do not consist, as Hertwig 
and Haeckel believed, of the isolated skeletal elements of various species 
of Plimodaria, but are the true “ houses ” of independent individual or- 
ganisms. What Hertwig and Haeckel observed were originally skeleton- 
less Phasodaria which had taken up the shells of Dictyochida into their 
substance. Herr Borgert gives a detailed account of Distephanus speculum 
— a species whose variations cover eighteen forms, to which specific rank 
has been granted. His memoir also includes an account of the minute 
structure of the parapyla in the central capsule of Phaeodaria and a 
note on Sagenoarium Chuni g. et sp. n. from the Atlantic. 
Pelomyxa viridis.* — Prof. A. G. Bourne gives an account of a new 
species of Pelomyxa found in a pond at Madras, and takes the oppor- 
tunity of making some remarks on the vesicular nature of protoplasm. 
The new species is about 1/10 in. in diameter, and is interesting not 
only from being larger than any known form of the Lobosa, but because 
of the presence of chlorophyll and symbiotic Bacteria. It should be 
noted that the bodies which Prof. Bourne regards as Bacteria were 
described by Greef as crystals of unknown composition, and by Leidy as 
exhibiting transverse striations. 
In describing the structure of his new form, the author uses the 
word protoplasm in the sense in which Butschli uses the word plasma. 
It designates the substance which Leydig calls spongioplasma, as dis- 
tinguished from hyaloplasma. He is inclined to support the view of 
Butschli that the plasma is the substance which forms the envelopes of 
the vesicles, and that it does not include their contents. He finds that 
he can distinguish in P. viridis between two varieties of non-contractile 
fluid-containing spaces, the vacuoles containing water, and the vesicles 
having chlorophyllogenous contents. 
The protoplasm of P. viridis appears to be perfectly homogeneous, 
and small portions of it may at times be observed at the periphery of 
the organism free from all contents, but the great mass of it forms a 
mere scaffolding for the numerous vesicles, and is, moreover, densely 
packed with Bacteria, to say nothing of its various other contents. The 
vesicles contain a fluid substance impregnated with chlorophyll. The 
vesicles and the Bacteria are to be regarded as bodies contained in the 
protoplasm, and the latter may flow out, leaving all its contents behind. 
When the protoplasm does flow out in this way some of the Bacteria 
soon follow, and may be seen to start an active movement ; and, if the 
outflow continues, the superficial vesicles leave the central mass and 
may be seen isolated in the hyaline protoplasm. 
The author discusses the protoplasmic movements, and states that 
the large pseudopodia are protruded at a velocity of about *75 mm. a 
minute ; Engelmann regarded a velocity of • 5 mm. as exceptionally 
rapid. The number of nuclei in P. viridis is enormous ; a large indi- 
vidual may, it is estimated, have as many as 10,000. He suggests that 
* Quart. Journ. Micr. Sci., xxxii. (1891) pp. 357-74 (1 pi.). 
