MIRACLES OF SCIENCE 



quantities of anti-toxins to neutralize the bacterial 

 poisons; the bacteriolysins tend to dissolve the dead 

 germs; the opsonins facilitate their ingestion by the 

 hosts of leucocytes always present in the blood; and 

 presently the invaders have been removed from the 

 tissues and their poison neutralized. In a word, the 

 capacity to form anti-bodies, which is a function of 

 the tissues, has been called into action. 



NATURE'S PRODIGAL SUPPLY OF ANTIDOTES 



No useful purpose would have been accomplished 

 in all this, however, were it not for a peculiar physio- 

 logical property of the tissues, in virtue of which 

 they do not limit their response to the mere balanc- 

 ing of the attack made by a bacterial enemy. That 

 is to say, when a group of germs with their modicum 

 of poison is forced into the midst of the body cells, 

 the cells do not content themselves with producing 

 merely enough antitoxin precisely to neutralize the 

 amount of toxin introduced, and enough opsonins 

 to insure the ingestion of this particular host of 

 bacteria and no more. Nature is by no means so 

 conservative as this would imply. She calls on the 

 cells to produce anti-bodies in all haste, and to con- 

 tinue producing them for some time after the precise 

 irritant in question has been eliminated. 



If a certain group of, say, typhoid germs has been 

 introduced, how can it be known that this is not a 

 mere advance guard, premonitory of the coming of 

 other hosts? Obviously the only safe course is to 

 assume that such is the case. 



So the cells go on for a time producing the anti- 



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