ZOOLOGY AND BOTANY, MICROSCOPY. ETC. 513 



appear after six weeks as the result of sub-culture. They increase slowly 

 in size during the following fortnight. These colonies are spherical, 

 projecting, wrinkled and greyish. They are composed of a tangled 

 mass of mycelial filaments, granular in appearance, and often deformed 

 by chlamydospores. At the extremities and on the walls of these 

 filaments large rounded or oval cells are formed by a process of budding. 

 The bud gradually becomes more and more constricted at its base and 

 finally becomes detached. These free double-walled cells then contain 

 three or four elements identical with the cryptococci found in pus. If 

 these results are verified, the causal organism of epizootic lymphangitis 

 belongs to the genus Endomyces. 



New Culture Medium for the Gonococcus." — D. Thomson has 

 devised a new culture medium for the gonococcus which, while giving 

 excellent primary culture, is eminently suitable for the preparation of 

 vaccines. The medium is made up as follows : — 1. Prepare nutrient 

 agar (2"5 p.c.) in the ordinary way with bouillon and Witte's pepton 

 (1 p.c), and render it + 6 acid. 2. Instead of adding to this 0-5 p.c. 

 sodium chloride as is usual, add all the salts natural to the human blood 

 (as in Ringer's solution) — namely, sodium chloride 1) grm., calcium 

 chloride • 25 grm., and potassium chloride ■ 42 grm. per litre. 3. Add 

 glucose 2 '5 p.c. This addition in some manner renders the growth 

 much profuse. 4. The nutrient agar with salts and glucose is then 

 tubed, about 4 c.cm. being added to each test-tube. 5. The sterile 

 tubed agar is melted in boihng water, and after allowing it to cool to 

 about 50° C, add 1 c.cm. of human plasma to each tube and mix 

 thoroughly by rolling the tube between the palms. Allow the medium 

 to solidify in a sloping position. For plating, the contents of three tubes 

 may be added to a Petri dish. 



Method of ohtaining Human Plasma. — When a supply of plasma is 

 required, draw off three-quarters of a test-tube full of blood with all 

 sterile precautions. Have a sterile centrifugal tube ready containing 

 2 c.cm. of a 2 p.c. solution of sodium citrate. Fill up this centrifugal 

 tube with the freshly drawn blood. Plug it with a sterile cork (keep 

 the corks in alcohol and burn off the alcohol before plugging) and cen- 

 trifugalize. When the corpuscles are driven down, pipette off the 

 supernatant plasma with a sterile 10 c.cm. pipette and add 1 c.cm. to 

 each tube of agar as indicated above. If the test-tube of blood is three- 

 quarters full there is sufficient left for the Wassermann test after filling 

 the centrifugal tube. 



'»"- 



Spontaneous Separation of Blood-clot from Walls of Containing 

 Vessel. t — A. D. Gardner calls attention to the common difficulty ex- 

 perienced in the obtaining of serum from blood owing to the frequent 

 refusal of the clot to separate from the walls of the containing tube or 

 cylinder. In the author's hands the following technique has given 

 uniformly good results : — 



Into the tubes or cylinders which are to receive the blood a small 



* Laucet, cxciii. (1917). 



t Lancet, cxciii. (1917) pp. 51-2. 



Oct. nth, 1017 2 M 



