26 MICRO-ORGANISBIS AS PARASITES, 



It is hardly necessary to say that cholera is one of those 

 diseases, where the conflict of the bacillus with the organism it 

 has invaded is swift and sharp, a pitched battle ending soon in 

 victory or death for one side or the other. The same may be 

 said of typhoid, scarlet, and yellow fever, measles, diphtheria, small- 

 pox, and pneumonia. Not only is the bacterium exterminated in 

 the system in cases of recovery in the latter diseases (with the 

 exception of pneumonia), but the field in which it grew seems 

 exhausted of the necessary nourishment required by the parasite, 

 and it is uncommon to see a person attacked a second time by 

 measles, scarlet fever, whooping-cough, and other zymotic diseases. 

 Of the manner in which the living tissues proceed to attack 

 the dangerous invaders of the body, Mr. Bland Sutton gives a 

 most interesting account, founded (as we may expect to find in 

 such researches) upon the most minute and patient investigations 

 on his own part, and on that of the foreign pathologists, on whose 

 authority Mr. Sutton says "The leucocytes (familiarly known as 

 white blood-corpuscles) may be likened to a defending army ; the 

 blood-vessels are their roads and lines of communication. Every 

 composite organism maintains a certain proportion of leucocytes, 

 as representing its standing army. When the body is invaded by 

 bacilli, bacteria, micrococci, chemical, or other irritants, information 

 of the aggression is conveyed by the vaso-motor nerves, and 

 leucocytes rush to the attack ; reinforcements and recruits are 

 quickly formed to increase the standing army, sometimes twenty, 

 thirty, or forty more than the normal standard. In the conflict, 

 cells die, and are often eaten by their companions ; frequently the 

 slaughter is so great that the tissue becomes hardened by the dead 

 cells, in the form of pus ; the recent activity of the cells being 

 testified by the fact that their protoplasm often contains bacilli, etc., 

 in various stages of destruction. These dead cells, like the corpses 

 of soldiers who have fallen in battle, later become hurtful 

 to the organism which in their lifetime they strenuously en- 

 deavoured to protect from harm. They are fertile sources of 

 septicoemia and pycemia, the pestilence and scourge so much 

 dreaded by operative surgeons." The analogy may seem at first a 

 little romantic, but its correctness will be shown by the facts 

 which will be placed before the reader. 



