EPIDEMIC CEREBROSPINAL MENINGITIS 247 



great tendency to the production of involution forms (Fig. 67), 

 many of the cocci becoming much swollen, staining badly, and 

 afterwards undergoing disintegration. This change, according 

 to Flexner's observations, would appear to be due to the pro- 

 duction of an autolytic enzyme, and he has also found that this 

 substance has the property of producing dissolution of the bodies 

 of other bacteria. The life of the organism in cultures is a 

 comparatively short one ; after a few days cultures will often be 

 found to be dead, but, by making sub-cultures every three or 

 four days, strains can be maintained alive for considerable periods. 

 On egg medium (p. 46), however, it survives for a considerable 

 time. The organism is 



readily killed by heat at . ' ' ' " «? . 



60" C., and it is also / " • •• • x v 



very sensitive to weak £ * m ..* 3 • V, 



antiseptics; drying for a t*» "".."*' »V \ 



period of a day has been i -'' ? • » . % f% 



found to be fatal to it. # " «* ., 't. •* '., »**fc 

 The facts established ac- » ,** ."*\. - **^\ • *- *' 



cordingly show it to be , *£%**' *'"* *• * J 



a somewhat delicate *ft . * . « -«•"'.' 



parasite. ,\ • •• .. i% i» ^t -J 



As stated above, the \ s ^ . "" .* "' »'* * %j 



organism occurs in the * . ».'«►_#.. / 



exudate in the meninges \, • !.- , j • ^ 



and in the cerebro-spinal \» *t/f £* % ' ** ^ 



fluid, and it can usually '*** i 2 _*• -^ 



be obtained by lumbar FlG . 6 7.— Pure culture of diplococcus intra- 

 puncture. In acute cases, eelhilaris, showing involution forms, 



especially in the earlier 



stages, it is usually abundant ; but in the later stages of cases 

 of more sub-acute character, its detection may be a matter 

 of difficulty, and only a few examples may be found after a 

 prolonged search. But it should be recognised that at any stage 

 microscopic examination and even cultivation may sometimes 

 give a negative result. In most cases the lesions are practically 

 restricted to the nervous system, but occasionally complications 

 occur, and in these the organism may be present. It has been 

 found, for example, in arthritis, pericarditis, pneumonic patches 

 in the lung, and in other inflammatory conditions associated 

 with the disease, and also occasionally in purpuric patches in 

 the skin, though the ordinary petechial eruption is of toxic 

 origin. In a small proportion of cases it may be obtained from 

 the blood during life. 



