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THE AMERICAN NATURALIST [Vol. LIV 



sideration here, are doubtless due to extensive phlebitis 

 and primary thrombosis of veins. In any case it is a 

 part of the circulatory system which breaks down, and 

 therefore we are warranted in placing this disease in 

 Table I. 



Item 4, ' ' Malaria," is fundamentally a disease of the 

 blood, and hence is placed here from "General diseases." 



All the evidence that the pathological anatomist has 

 leads to the view that yellow fever, typhus fever, relaps- 

 ing fever and miliary fever are blood diseases. They 

 have the lesions of septicemias, or are transmitted by 

 biting insects, or both. 



Items 53 and 54, "Leukemia" and "Anemia, chlo- 

 rosis," represent breakdowns of the blood or blood-form- 

 ing organs of the body. They are taken from Class I of 

 the International Classification. 



In the International Classification item 116, "Diseases 

 of the spleen," is placed under the general rubric of 

 "Diseases of the digestive system." This is a good 

 illustration of the biological absurdities which appear 

 in the statistical classification now used. Just what the 

 spleen has to do directly with digestion does not appear. 

 It is primarily a blood-forming organ. 



Bubonic plague is a disease of the lymphatic system. 

 The great epidemics of fatal type are characterized by 

 the pneumonic and septicemic forms. On the whole, it 

 seems best to place this disease here. 



It is evident from the data of Table I that where death 

 ensues from a breakdown of any part of the circulatory 

 or blood systems it is preponderantly the heart itself 

 which is at fault. Diseases of the arteries, which, gen- 

 erally speaking, mean arteriosclerosis, come second in 

 importance. The other causes listed are of relatively 

 minor importance. The relatively enormous rates for 



reasons for these differences, since the main object in this 



