CONJUNCTIVITIS. 20I 



In a number of the earlier cases of epidemic cerebrospinal 

 meningitis the pneumococcus was described as the organism 

 present, but later observations made in different parts of the 

 world show that the organism usually concerned is undoubtedly 

 the diplococcus intracellularis meningitidis. In acute cases, and 

 especially in the earlier stages, it is usually present in large 

 numbers, but in the more chronic it occurs sparsely, and its 

 presence may be demonstrated only with difficulty. The organ- 

 ism can usually be obtained by means of lumbar puncture. Cer- 

 tain sporadic cases of meningitis are also due to this organism, 

 and it is extremely probable that the diplococcus of simple basal 

 meningitis in children described by Still is merely a modification 

 of this meningococcus. 



Conjunctivitis. — A considerable number of organisms are 

 concerned in the production of conjunctivitis and its associated 

 lesions. Of these a number appear to be specially associated 

 with this region. Thus a small organism, generally known as 

 the Koch-Weeks bacillus, is the most common cause of acute 

 contagious conjunctivitis, especially prevalent in Egypt, but also 

 having a very wide distribution. This organism morphologically 

 resembles the influenza bacillus, and its conditions of growth 

 are even more restricted, as it rarely grows on blood agar, the 

 best medium being serum agar. Another organism exceedingly 

 like the previous, apparently differing from it only in the rather 

 wider conditions of growth, is Muller's bacillus. It has been culti- 

 vated by him in a considerable proportion of cases of trachoma, 

 but its relation to this condition is still a matter of dispute. 

 Another bacillus which is now well recognised is the diplo-bacil- 

 lus of conjunctivitis first described by Morax. It is especially 

 common in the more subacute cases of conjunctivitis. Eyre 

 found it in 2.5 per cent of all cases of conjunctivitis. Its cultural 

 characters are given below. The xerosis bacillus (Chap. XVI.) 

 has been found in xerosis of the conjunctiva, in follicular con- 

 junctivitis, and in other conditions; it appears to occur some- 

 times also in the normal conjunctiva. Acute conjunctivitis is 

 also produced by the pneumococcus, epidemics of the disease 

 being sometimes due to this organism, and also by streptococci 

 and staphylococci. True diphtheria of the conjunctiva caused 

 by the Klebs-LbfHer bacillus also occurs, whilst in gonorrhoeal 

 conjunctivitis, often of an acute purulent type, the gonococcus 

 is present. 



