THE AMERICAN NATURALIST. [Vol. LIV 



entirely different general classification of the causes of 

 death on a reasonably consistent biological basis. The 

 underlying idea of this new classification is to group all 

 causes of death under the heads of the several organ 

 systems of the body, the functional breakdown of which 

 is the immediate or predominant cause of the cessation 

 of life. All except a few of the statistically recognized 

 causes of death in the International Classification can be 

 assigned places in such a biologically grouped list. It 

 has a sound logical foundation in the fact that, biolog- 

 ically considered, death results because some organ sys- 

 tem, or group of organ systems, fails to continue its func- 

 tion. Practically, the plan involves the reassignment of 

 all of the several causes of death now grouped by vital 

 statisticians under heading "I. General diseases." It 

 also involves the re-distributing of causes of death now 

 listed under the puerperal state, malformations, early in- 

 fancy, and certain of those under external causes. 



The headings finally decided upon for the new classi- 

 fication tire as follows : 



I. Circulatory system, blood, and blood-forming 

 organs. 



II. Respiratory system. 



III. Primary and secondary sex organs. 



IV. Kidneys and related excretory organs. 

 V. Skeletal and muscular systems. 



VI. Alimentary tract and associated organs concerned 



in metabolism. 

 VII. Nervous system and sense organs. 

 VIII. Skin. 

 IX. Endocrinal system. 

 X. All other causes of death. 



It should be emphasized before presenting the tables 



