210 BIOLOGY AND TECHNIQUE 



other organisms. Such fluid may range from slight turbidity to 

 thick purulence. The cells in such fluid consist almost entirely of 

 polynuclear leucocytes during the acute stages. Smears should he 

 made immediately and stained by Gram. If Gram-positive organisms 

 are present, they can immediately be recognized, and cultures taken 

 accordingly. In epidemic meningitis the Gram-negative meningo- 

 cocci will be found mostly intracellular, but some also extracellular. 

 Sometimes a very prolonged search must be made before any 

 meningococci can be found, because these organisms readily undergo 

 autolysis. In the fluid from an acute case of meningitis in which 

 many polynuclear leucocytes are present, and no organisms can be 

 found, it is pretty safe to suspect epidemic meningitis, since we 

 have on a number of occasions encountered fluids of this kind in 

 which no organisms could be seen. Cultures should, in all cases, 

 be taken even when the organisms are found, since this may be of 

 value in determining the meningococcus type, in finding out whether 

 the particular meningococcus is agglutinable in the polyvalent serum 

 used, and the collection of the type of meningococci which are 

 present in an epidemic is a part of the bacteriologist's contribution 

 to the successful production of sera. The cultures are best taken 

 on plates of hormone agar with 0.5 per cent glucose, and hemolyzed 

 blood or ascitic fluid added. 



Pneumococci, streptococci, influenza bacilli, etc., may be cul- 

 tivated by appropriate methods. 



The cytological character of the fluid and the relationship of 

 cells to bacteria should always be determined since this may have 

 a certain amount of prognostic significance. 



Examination of Urine. Bacteriological examination of the urine 

 is of value only when specimens have been taken with sterile 

 catheters, and care has been exercised in the disinfection of the 

 external genitals. This is particularly important in the female. 

 Many of the numerous finds of bacillus coli in urine are unquestion- 

 ably due to defective methods of collecting material. Urine should 

 be centrifugalized and the sediment examined morphologically and 

 pour-plates and surface smears made upon the proper media. 

 If necessary, animal inoculation may be done. In examining urine 

 for tubercle bacilli, special care should be taken in staining methods 

 so as to differentiate from Bacillus smegmatis. When the question 

 is one of infection of one kidney alone the specimens must of course 

 be obtained by ureteral catheterization. 



