112 THE PATHOGENIC M1CROCOCCI. 



guinea-pigs. Dogs and rabbits are immune. Intrapleural 

 injections in susceptible animals result in a decided pleuritic 

 effusion with formation of fibrinous membranes, intense con- 

 gestion of the lungs on the injected side, great enlargement 

 of the spleen, and general involvement of the blood (septi- 

 caemia) and internal organs ; the bacillus being found every- 

 where. 



EPIDEMIC CEREBROSPINAL MENINGITIS. 



III. Diplococcus Intracellularis Meningitidis. 



This organism was discovered by Weichselbaum, in 1887, 

 in pus-cells (polymorphonuclear leucocytes) of the cerebro- 

 spinal exudate of cases of epidemic cerebrospinal meningitis. 



Morphology. The micrococcus occurs in bunches or in 

 chains of three or four elements, the elements in the chain 

 showing marked variation in size. Stains with all the anilin 

 dyes and is decolorized by Gram's method. It shows marked 

 variation of the different elements in their power of taking 

 color ; some elements being deeply stained, others scarcely at 

 all. The organism has a low vitality ; exposure in the dry 

 state for twenty-four hours to direct sunlight at the body 

 temperature, 37 C., is sufficient to kill it. At the room 

 temperature it is killed in seventy-two hours when dried. 



To obtain cultures from man, of this bacillus, what is known 

 as lumbar puncture of the spine must be made. The patient 

 is placed on the left side very much in the same position as is 

 used for intraspinal cocainization, the skin of the patient and 

 hands of the operator are thoroughly sterilized, and an ordi- 

 nary antitoxin-serum needle is introduced into the spinal canal, 

 between the second and third lumbar vertebra?, the skin 

 being pierced a little to the right of the spinous process. The 

 needle is driven in for 4 cm. in a child, and 7 to 8 cm. in an 

 adult, until the spinal canal is reached, when the spinal fluid 

 is allowed to drop into a clean sterilized test-tube. From 5 

 to 15 c.c. of fluid are generally taken for examination. 

 Cover-glasses are prepared and a number of cultures are made. 

 This puncture seems to be followed by no ill effect. 



