The President's Address. By G. S. Woodhead. 223 



does not appear to form chains as does the pneumococcus. It is 

 said that when this organism is grown on blood agar it may be 

 surrounded by a capsule similar to that met with in the pneumo- 

 coccus passed through the blood of a living mouse. I have 

 succeeded in isolating such an encapsuled organism from the 



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Fig. 25. — Diplococcus intracellularis meningitidis of Weichselbaura 

 lying in and between the cells in the fluid withdrawn by lumbar 

 puncture from a case of cerebro-spinal fever. Drawing x 800 

 from a specimen prepared by Captain J. F. Gaskell, M.D. t 

 R.A.M.O., T. 



throats of " contact " cases, an organism that has many of the 

 characters of the meningococcus. Successful cultures of this 

 coccus from the cerebro-spinal fluid are fairly characteristic in 

 appearance. They occur as moist, smooth, rapidly growing 

 colonies, making their appearance in ten or twelve hours, and 

 extending rapidly to form somewhat thick, greyish colonies, 

 opaque in the centre, but with a more translucent zone at the 

 periphery, the margin being smooth, regular, and fairly sharply 

 defined. Secondary cultures made from these colonies grow 

 profusely, often running together and forming a moist, grey, 

 almost slimy-looking mass. This organism, grown on media 

 containing maltose, glucose, or galactose, especially the first of 

 these, and some indicator, of which neutral red appears to be 

 the most satisfactory, is found to produce acid, and it is by this 

 production of acid from these sugars that it is said to be distin- 

 guished from the Micrococcus catarrhalis, one of the Gram-negative 

 diplococci for which it may be mistaken under the Microscope. 

 There is, however, this further difference, that the Micrococcus 

 catarrhalis grows freely at the temperature of 22° 0. or 23° C, 

 a temperature said to be unfavourable to the growth of the 



R 2 



