Life-liistory of the Meningococcus. 369 



the English text-books, faithful to the general tradition that 

 bacterial morphology does not merit serious study. xVnd in no 

 description of the meningococcus that I have seen in any language 

 has there appeared any account of observations of growth of this 

 organism, or of the giant forms, on the warm-stage, an omission, as 

 will be seen, which explains a good deal. 



From this brief resume of the present state of knowledge of 

 the morphology of the meningococcus, there is clearly a good deal 

 to suggest that further enquiry was necessary as to the supposed 

 botanical position of that organism. We have here, for example, 

 an organism which varies very greatly in size, which sometimes 

 occurs in chains, whether accidentally produced or not, and which 

 sometimes has a central bright spot, giving in unstained prepara- 

 tions a clear space, strongly suggestive of a false spore. And, 

 finally, we have giant forms appearing repeatedly in young suit- 

 able cultures of a few liours old, which, on that account alone, 

 are most unlikely to be involution forms ; as well as very great 

 variation in size of " normal " meningococci, not only in cultures 

 from one case, but also in cultures from one case as compared with 

 cultures from another case. Anyone, for example, who has studied 

 the morphology of Gordon's so-called strain No. 2 in liquid cultures 

 cannot but have been struck with the large size of the normal 

 individuals present, as compared with those often seen in cultures 

 from strain No. 1. So aljerrant, in fact, are they often found to be, 

 that it is difficult to believe that they are true meningococci, either 

 in size or shape. 



So much for current descriptions of meningococcal morphology, 

 as sLudied mainly on solid media. 



AVe come now to my own studies of the morphology of the 

 meningococcus in liquid media, subcultured from solid media. And 

 here let me say, that in attempting to determine the true botanical 

 position of the meningococcus, or of any other reputed bacterium, 

 it is often fatal to restrict one's observations to growth on solid 

 media only, however convenient these may be for purposes of 

 identification. 



In the case of the meningococcus, I have so far only once 

 succeeded in obtaining free growth on solid media of the organism 

 we will now show you, although I had no difficulty in obtaining 

 free growth in thirty-six consecutive acute cases of cerebrospinal 

 meningitis from primary colonies on serum-agar. 



In every case the meningococcus has been isolated and fully 

 identified, by its staining reactions, its morphology, its sugar re- 

 actions, and its serological reactions, and by certain well-defined 

 cultural reactions, many of which are not in the text-books. I have 

 not found the largest forms in any case apart from the meningococ- 

 cus, and in no case has the meningococcus been found without these 

 organisms being also found. I have never been able to cultivate 



