Preliminary remarhs on immunity in animal kingdom 45 



MPn 



^Pubject of clearing up this question. He guarded himself against the 

 objections justly made against his predecessors and conducted his 

 experiments under unexceptionable conditions. He injected several 

 species of micro-organisms into the veins of rabbits and into the 

 subcutaneous tissue of guinea-pigs. At various intervals he per- 

 formed laparotomy on these animals, pulled out the bladder and 

 rew oif the urine in such a fashion that no trace of blood could 

 et into it. The results were most conclusive. Never, when the 

 experiment was conducted under the rigorous conditions just men- 

 ■tioned, did the micro-organisms traverse the kidneys of resistant 

 animals nor were they ever met with in their urine. 



Metin's researches on the passage of mici'o-organisms through the 

 liver in refractory animals gave the same results. In no case was he 

 able to find in the bile any of the organisms that had been injected 

 into the blood or under the skin. At the end of his memoir 

 Me tin sums up his results as follows : " (1) The kidneys and the 

 iver are impermeable to bacteria introduced into the organism, 

 ubcutaneously or intravenously ; (2) when the culture tubes contain 

 colonies of the injected micro-organism, it is because there has been 

 a certain amount of blood in the fluid inoculated, this being an 

 indication of a vascular or epithelial lesion, either mechanical or 

 chemical." We were present at M. Metin's experiments and can bear 

 witness to their exactitude. 



There can no longer be any doubt then on this point. The 

 elimination of the micro-organisms from the refractory animal 

 takes place, as indicated in Wyssoko witch's first investigation, neither 

 by the kidneys nor by the liver. Some observers have asserted that 

 this elimination may take place by the sudoriparous glands. Thus, 

 Brunner^ made experiments with young pigs and cats into which he 

 had previously injected micro-organisms, for the most part patho- 

 genic. Then producing a transpiration by means of pilocarpin, he 

 *' cultivated " the sweat and noted the development of the same 

 bacteria as he had introduced into the blood. In a single experiment 

 with a saprophyte {Coccohacillus prodigiosus) he obtained a positive [49] 

 result, from which he concludes that the refractory animal gets rid of 

 bacteria which circulate in its blood by way of the sudoriparous 

 glands. It is scarcely allowable to draw any conclusion from this 

 experiment from the fact that the snout of the pig, the seat of the 

 transpiration, is very liable to small vascular lesions which might 

 1 Berl klin. Wchnschr., 1891, S. 505. 



