CHAPTER XI. 



THE INTERNAL SECRETIONS IN THEIR RELATION 

 TO IMMUNITY. 



THE UNITY OF CELLULAR LIFE. 



IN the present state of our knowledge the inaccuracy 

 of the view that bacteria per se cause disease independently 

 of the toxins they generate hardly needs to be emphasized. 

 Apart from the mechanical effects which the accumulation 

 of micro-organisms in the blood may cause, every disease 

 distinctly traceable to them is attended with intoxication. 

 Whether there occur after infection a rapid multiplication and 

 a wide-spread distribution of germs, as in anthrax and septi- 

 caemia; or a more localized though prodigious multiplication 

 of bacteria, as in cholera and pneumonia; or, again, an abso- 

 lutely circumscribed multiplication at the site of infection, 

 as in diphtheria: phenomena such as toxins alone can cause 

 invariably appear. In the entire sphere of bacterial activity 

 is encompassed that which is manifest in all Nature: a dis- 

 play of energy through change. Micro-organisms, by their 

 growth and multiplication, not only generate products of 

 metabolism, bu these, by their physico-chemical effects upon 

 surrounding liquids, engender the fermentative processes which 

 underlie all infectious diseases, "infectious" only in the sense 

 of the.ir being transmissible. 



Again, we can legitimately assume that the reactions 

 caused by micro-organisms in the body-fluids are similar to 

 those brought on by the venom of snakes, insects, and toxic 

 plants. Unity of cellular life applies to and includes all path- 

 ogenic cells, whether these be of animal or vegetable origin; it 

 applies likewise to their metabolism, the toxic elements gen- 

 erated by them, and to the reactive effects on their surround- 

 ings. While Weir Mitchell, Reichert, and others have dem- 

 onstrated the albuminoid nature of the toxic principles of 

 snake-venom, Roux has emphasized the analogy between these 

 principles and the toxalbumin of diphtheria. The urticaria 



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