MICROBE OF INFANTILE PARALYSIS 259 



planation is plain. The child is playing, per- 

 chance in the soil, at the very door of its own 

 home. The germ is in the soil. By it the child is 

 infected and has the disease. In the same soil the 

 child may have played a hundred times before and 

 escaped. This time it happens to be caught. 



Infantile paralysis has two modes of infection. 



One by means of some slight wound or scratch. 

 The wound may be on the hand, forearm, or, if the 

 child goes barefoot, on the foot. Having such a 

 wound, the child plays in the soil. The germ, 

 being in the soil, comes in contact with the wound. 

 It hence enters the circulation, and, through some 

 nerve, finds its way to some ganglionic center in 

 the marrow of the spinal column. Once here, the 

 disease is sure. 



The other mode of infection is by way of the 

 nostrils. The germ is undoubtedly among the very 

 smallest. Under rare circumstances, it rises on 

 particles of dust and floats in the air. Breathed 

 into the nostrils, it finds its way directly to the 

 spinal cord where it joins the base of the brain. 

 Once here, again the disease is sure. 



Infection may possibly be caused, also, by the bite 

 of some insect which has previously bitten a person 

 or animal having the disease. In such case the in- 

 sect inflicts the wound and inserts the germ at the 

 same instant. 



By any mode of infection the germ finds its 

 natural nexus, the spinal cord. Here it rapidly 

 multiplies into millions. By their life processes 



