COMBATING PARASITIC BACTERIA. 165 



lead to the belief that they are the cause of these 

 diseases. The only one of very common occur- 

 rence is a species known as Amoeba coli, which is 

 found in cases of dysentery. In a certain type 

 of dysenterythis organism is so universally found 

 that there is little doubt that it is in some very 

 intimate way associated with the cause of the dis- 

 ease. Definite proof of the matter is, however, 

 as yet wanting. 



On the side of plants, we find that several 

 plants of a higher organization than bacteria may 

 become parasitic upon the body of man and pro- 

 duce various types of disease. These plants be- 

 long mostly to the same group as the moulds, 

 and they are especially apt to attack the skin. 

 They grow in the skin, particularly under the hair, 

 and may send their threadlike branches into some 

 of the subdermal tissues. This produces irrita- 

 tion and inflammation of the skin, resulting in 

 trouble, and making sores difficult to heal. So 

 long as the plant continues to grow, the sores, of 

 course, can not be healed, and when the organ- 

 isms get into the skin under the hair it is fre- 

 quently difficult to destroy them. Among the 

 diseases thus caused are ringworm, thrush, alopecia, 

 etc. 



CHAPTER VI. 



METHODS OF COMBATING PARASITIC BACTERIA. 



THE chief advantage of knowing the cause of 

 disease is that it gives us a vantage ground from 

 which we may hope to find means of avoiding its 

 evils. The study of medicine in the past history 



