MIRACLES OF SCIENCE 



world is subject. One fifth of all deaths occur in early 

 infancy. 



A NEW REMEDY FOR CATTLE PLAGUE 



Reference has been made to Professor Ehrlich's 

 attempted cure of sleeping sickness. This very fatal 

 disease, which fortunately is confined to the tropics, 

 was studied at first hand by a commission under Dr. 

 Robert Koch, who discovered that the agent of its 

 transmission from one subject to another is the tsetse 

 fly. The germ that causes this disease as already 

 noted, is not a bacterium but a protozoon; that is to 

 say a single-celled animal organism of the lowest 

 type. It has come to be known in recent years that 

 many other tropical diseases are due to similar proto- 

 zoal organisms. The plasmodium of malaria is also 

 of the same type. 



The protozoal germs differ from the bacteria in that 

 they for the most part have a double cycle of life 

 transformations, the two stages of their develop- 

 ment being passed in the organisms of different ani- 

 mals. In the case of the malaria plasmodium, for 

 example, as was first demonstrated by the Englishman 

 Dr. Ronald Ross, one stage of development is passed 

 in the organism of a mosquito of the genus Anopheles, 

 which transmits the germ to the human subject in 

 whose blood stream it undergoes the remaining 

 stages of its development. 



The various tropical contagious diseases are almost 

 without exception transmitted by parasitical insects, 

 yellow fever, for example, by a mosquito of a different 

 genus from that which transmits malaria, the Asiatic 



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