PROaRESS OF MICROSCOPICAL SCIENCE. 
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Palmodidyon viride in Britain. — Mr. Edward Parfit has written 
to ' Grevillea ' saying that he has found this plant in the Exeter 
canal. He says : " Not knowing the plant myself, and after search- 
ing all the works on the subject I had at my command, I forwarded 
specimens to my friend Professor Dickie, of Aberdeen, who kindly 
writes me this : ' The plant is Palmodidyon viride (Kiitzing), and so 
far as I know new to the British list.' The plant, where it has 
sufficient room to develop itself, spreads over the bottom, in water about 
six inches deep ; beyond this it comes in contact with Elodes cana- 
densis, over which it creeps, and extends its growth from branch to 
branch into deeper water. In this extension it has first the appear- 
ance of a Conferva, which I at first took it to be ; but the moment I 
touched it, after taking some from the water, I found from the soft 
slimy feel that if a Conferva it was new to me, and the microscope 
soon revealed the true character. When the plant grows on the 
bottom it shows one continuous green membrane, stretched tight over 
the bottom, but when it comes in contact with other plants it throws 
out filaments, the thickness of which is difficult to make out on 
account of their adhesive nature ; for wherever they touch it is 
matter of impossibility to separate them. The membrane forming 
the filaments is structureless, but the spherical cells form more or 
less moniliform threads sometimes running in parallel lines, at other 
times forming an irregular net-work on the inside of the filaments. 
These cells sometimes divide into two portions, at others into four, and 
in most of the mature cells may be observed four cellules." 
Formation of Fibrin from the Med Blood-corpusdes. — M. Landois, 
according to the ' Medical Eecord ' of November 18, describes the 
formation of fibrin as being dependent on the dissolved corpuscles. 
If a drop of defibrinated rabbit-blood be brought into a drop of frog's 
serum, the cells aggregate together, and become sticky on their sur- 
faces. The cells soon become globular, and those cells lying towards 
the periphery allow the blood-colouring matter to pass out. This 
discolouring gradually extends towards the centre of the drop, and at 
last only a heap of stroma remains. The stroma-substance is very 
tough and viscid. At first the contours of the cells can be detected ; 
and, when the stroma has been agitated to and fro, the cellular con- 
tours disappear, and viscous fibres and stripes are observed. Step by 
step the formation of fibrous masses from the dissolved mammalian 
cells can be observed. The author thinks this fibrin should be called 
" stroma-fibrin " in opposition to the ordinary fibrin or plasma-fibrin, 
which is formed without solution of the blood-corpuscles. The two 
kinds of fibrin may possibly be chemically distinguished from each 
other. In transfusion, if dissolution of the cells occur, then, of 
course, the formation of stroma-fibrin may take place. The coagu- 
lation occurs the sooner, the more serous the blood. Animals in a 
state of asphyxia, into whom heterogeneous blood was introduced, 
showed the most extensive coagulation. 
The Anatomy of the Ear. — At a meeting of the Medical Society 
in Vienna, in the beginning of October (a report of which is given in 
the ' Allgemeine Wiener Medizinische Zeitung ' for October 20), Pro- 
