376 



BACTERIOLOGY OF THE EYE 



We must not make any rigid division of the cases, as the distri- 

 bution of the septic material is not according to any absolute rule. 



In forming any opinion, from microscopical appearances, as to endogenous infec- 

 tions, it must be remembered that a further post-mortem increase is possible in the 

 bacteria lying in the vessels, and also in those in the metastatic nodules. Accord- 

 ing to Canon, Lenhartz, and others, the number of the bacteria in the blood 

 increases in septic pyaemia just before death. After death the numbers in the case 

 of some bacteria may be enormous. Among the pyogenic ones the Streptococci 

 may so increase that the vessels are quite filled, and we have the appearance of 

 an injection preparation. The post-mortem nature of these changes is shown by 

 the fact that the intravascular masses do not correspond to any inflammatory or 

 degenerative changes in the tissues around. This growth of bacteria is freest in the 







. METASTATIC STREPTOCOCCAL NECROSIS OF BOTH RETINAE 

 IN A FATAL CASE OF SEPTIC 



FIGS. 85 AND 



Large numbers of Streptococci lie in the subretinal space on the coroid, which itself is free 

 from metastases (cocci are violet). 



veins, which are well known to contain the greatest amount of the blood after death. 

 In the case of the larger, more compact masses of cocci in otherwise healthy veins, 

 we can at once exclude a metastasis having occurred here just before death, and not 

 having led to' any inflammatory reaction, for such a mass would have stuck in the 

 capillaries. 



Herrnheiser and Axenfeld have recorded cases showing very free post-mortem 

 growth of bacteria in the eye, and have emphasized the difference between such 

 conditions and the true metastases. 



The human retina is not very rich in vessels, and its special affinity 

 for the deposition of organisms raises the question, What causes are at 

 work in producing this state of affairs ? 



