ENDOGENOUS INFECTIONS 379 



in those cases in which Picot and Romer inoculated one eye. 

 Rb'mer was able to show that in the second eye the bacteria in question 

 could be found in large numbers, and in a comparatively short time, 

 but that is far from being a clinical demonstration of an inflammation 

 or metastasis. After an inoculation of one eye with tetragenus, 

 a metastatic inflammation of the other, resulting in healing, only 

 occurred in one of Picot's cases. Such, however, can be obtained 

 with certainty if we inject the organisms into the blood-stream, 

 especially if we inject into the jugular vein. 



Pechin and Phasalix (Soc. de Biol, October. 1898; Ann. d'Ocul, 

 cxx., p. 387) obtained a double-sided metastatic ophthalmia in a dog 

 after the injection of the bacilli of rabbit's septicaemia into the jugular 

 vein. Lagrange (Soc. Franc. d'Oph., 1898, p. 92) obtained a tuber- 

 culous iritis by injecting tubercle bacilli into the carotid artery. A 

 large number of such experiments have been performed by Stock. 



The predilection of the uvea of the rabbit, which seems to be 

 exclusive for many kinds of organisms, especially the tubercle bacillus, 

 is q, point of great interest. It is also remarkable how often Stock 

 observed that these lesions healed up in spite of the use of very 

 virulent organisms. Still more remarkable was the fact that nodules 

 in the choroid were milder, and healed more rapidly and completely 

 than inflammations in the ciliary body and iris. This shows that the 

 healing of such endogenous inflammations does not infer an infection 

 with attenuated organisms, but that even highly virulent organisms 

 can be made innocuous, not so much by their being killed out as by 

 their encapsulation in scar tissue. In any case they can remain in 

 the tissues in a state of great virulence long after clinical healing has 

 occurred. An interesting experiment in this connexion, and also an 

 important one regarding the healing in and latency of virulent bacilli 

 in the eye, is given by Stock, who showed that the transference of a 

 piece of iris infected with hsematogenous tuberculosis, appearing clinically 

 to be completely healed, would produce a severe tuberculosis in the 

 eye of another animal. This also explains how these endogenous 

 uveal affections (as also those of the sclera and cornea), often due to 

 tuberculosis in man, so freely recur, for the bacilli become encapsuled 

 in the tissues, and on a suitable occasion again become active. 1 



Stock's experiments certainly have shown that tuberculosis in the 

 rabbit, when it affects the blood-stream, can produce an extraordinary 



1 The encapsulation and prolonged latency of the pyogenic organisms has not yet been 

 proved for the eye ; it cannot be excluded, as it is accepted as occurring in other organs by 

 the surgeons. 



