202 PROCEEDINGS OF SOCIETIES. 
with carmine solution after the manner of Professor Beale. He 
also showed some sections of epithelioma of the tongue with 
polarised light. In these sections it was observed that the healthy 
muscular fibres polarised the light, while the diseased parts did 
not doso. Dr. Collis accounted for this by the greater density of 
the sound parts. It is well known that cancerous and similar 
morbid cells of large size are of great tenacity. In fact, it would 
appear as if the proper substance which should have formed a 
healthy cell went to form this much larger and diseased cell; 
consequently the latter is found to be more perishable, more easily 
acted on by chemical re-agents, and less dense. Dr. Collis believed 
that in doubtful cases this additional means of diagnosis would be 
of some value. 
Rev. E. O’Meara drew attention to and pointed out the charac- 
teristic marks uf several new Diatomacex discovered by him in 
the late gathering made by Dr. E. Perceval Wright off Arran 
Islands. These were named by him Coscinodiscus fasciolatus, 
Stauroneis rhombica, and Cocconeis concifera, descriptions of which 
will appear in this Journal. 
21st February, 1867. 
Dr. John Barker drew attention to a minute rhizopodous form 
which seems to present a new generic type. This was extremely 
minute, non-testaceous, broadly-subelliptic in outline, giving 
origin, at the extremities, to a somewhat crowded, slightly branched 
tuft of slender filiform pseudopodia. These tufts did not emanate 
from directly opposite points, but somewhat obliquely as regards 
each other. A comparatively large, not exactly central, amber- 
coloured oil-like globule was immersed in the substance of the 
body, the rest of which was colourless, exhibiting little of struc- 
ture or other differentiations. The pseudopodia were very slow 
and sluggish in their movement or change. Thus it might be 
seen that this organism might be defined, so to speak, as repre- 
senting a non-testaceous Amphitrema (Arch.), bearing a relation- 
ship to that form somewhat comparable to that of Plagiophrys to 
Pseudodiffilugia (Schlamb.). 
Dr. Moore showed a Cthonoblastus (Kiitz.) = Microcoleus 
(Harv.), taken in the botanic garden, and adverted to the relation- 
ship of that genus to Oscillatoria. 
Mr. Woodworth showed a number of photographs of polari- 
scopic objects (crytals) taken most successfully, and showing all 
the characters of striation, &c., evinced by these objects in a very 
delicate manner. 
Dr. Frazer mentioned another instance which had occurred to 
him of a singular mistake on the part of the uninitiated in taking 
portions of the pulp of an orange for intestinal worms. A gentle- 
man had forwarded to him what turned out to be some shreds of 
the membrane of the cells of the pulp of an orange, and who had 
