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should not lightly be undertaken or undergone. It is, of course, a 

 source of scientific congratulation that so many persons should be 

 not only willing, but anxious to be operated on, but they should, I 

 think, be explicitly informed by doctors that the treatment is only 

 in the experimental stage, that its curative effect is far from certain, 

 while its dangers are grave and numerous. With the exception of 

 Pasteur's experiments for hydrophobia, it is the first time that 

 experiment on the human subject has been sanctioned by the 

 public, and I doubt very much if they knew more of the subject 

 whether they would so cheerfully submit to it. Various theories 

 have been suggested to explain the method by which poisonous 

 germs develop in the system, and there generate chemical poisons. 

 There is no doubt a continual struggle is taking place in the 

 system between the healthy cells in the blood and tissues of the 

 body, and the poisonous germs which we unconsciously breathe in 

 with the air and swallow with our food. In a perfectly healthy 

 body the foreign germs seem to be actually devoured and digested 

 by the white blood corpuscles, and are rendered absolutely 

 innocuous. But in caseswhere the system is unhealthy or enfeebled, 

 the poisonous microbes become in their turn the attacking party 

 and destoy the blood cells, consume their nutriment, and finally 

 generate a chemical poison which effects the whole system and 

 induces illness. This at least is the theory of iVIetschuikoff, 

 Armand, Kuffer, and others, though I must tell you it is vigorously 

 contested by other scientists. This struggle or battle between the 

 healthy cells and the intruders has been admirably depicted by M 

 Metschnikoff who has not only (microscopically) witnessed this 

 conflict, but has made excellent diagrams of the resnlt of his 

 observations. In the diagrams now before you, copied from jNF. 

 Metschnikoff, may be seen the intrusive germs beset, devoured, 

 and actually digested by tlie blood cells, while in some may be seen 

 a blood cell attacked and destroyed by the microbes. 



The amoeboid cells, whose beneficent fmictions it is to prey upon 

 and devour inimical germs, are termed phagocytes (Gk. pliagein, to 

 eat) ; they are subdivided into macrophages, large or tissue cells, 

 and microphages, small cells. In an interesting article by Dr. 

 Alfred Schofield on this subject, he tells us it is believed that the 

 process by which a tadpole loses its tale is due to the voracious 

 instincts of these phagocytes, and those germs which prey upon all 

 dead organic matter, and which commence their work the moment 

 that life is extinct. It is a remarkable fact that during life the 

 animal body is able to defy those special microbes known as decay- 

 producing bacteria or saprophytes. 



Dr. Armand Buffer has published some highly interesting notes 

 of investigations made by him concerning the conflict between the 



