760 THE POPULAR SCIENCE MONTHLY. 



proof, that the death rate among these two classes, the Irish and 

 the negroes, is much higher than that of the general population. I 

 have not at hand statistics which will conclusively prove this fact, 

 and will only quote the tables prepared by General Walker, based 

 upon the United States census of 1870, in which he shows that 

 while the Irish constituted three hundred and thirty-three per 

 thousand of the foreign population, they contributed four hun- 

 dred and ten to every thousand foreign-born decedents, thereby 

 largely exceeding their due proportion. 



If we accept the opinion alluded to as a fact, we are brought 

 face to face with the paradoxical condition of a large proportion of 

 persons reaching extreme longevity among classes noted for a low 

 average longevity. How to account for this apparent anomaly is 

 a question of interest. But one explanation suggests itself to me, 

 and this I believe to be, in the main, the true one namely, that 

 the centennarians of the classes named owe their great age to fa- 

 vorable heredity, a natural life-force and power of endurance trans- 

 mitted to them by their ancestors, which enabled them to with- 

 stand or overcome the unfavorable environment which carried off 

 a large proportion of their respective races ; while, on the other 

 hand, the admittedly higher average longevity of the native whites 

 is to be accounted for by their more favorable surroundings and 

 mode of life, better hygiene in health and care when sick, whereby 

 the vitality of the weak, the sickly, and the young is conserved, 

 and many years of life are added to the average. If this explana- 

 tion be accepted as the correct one, it suggests the law, which is 

 also warranted by a wider observation, that extreme individual 

 longevity depends chiefly upon favorable heredity, while a high 

 average longevity is promoted mainly by a favorable environment. 



As the result of his studies of the native calendar of Central America and New- 

 Mexico, with special reference to linguistics and symbolism, Dr. D. G. Brinton 

 believes that the system of the peoples to whom it appertained was in a certain 

 sense philosophic; that it grew out of ripe meditation on the agencies which 

 direct and govern life; and that it was merely veiled not smothered in the 

 symbolism which has been transmitted to us, and which they found it convenient 

 to throw around it, in presenting it to the unlearned. The twenty potencies or 

 agencies, fixed at that number for a reason which the author determines, follow 

 each other in the sequence in which they were believed to exert their influence on 

 the life or existence, not of man only, but of things and of the universe itself. 

 This opinion exerted a strong constructive and directive influence on the national 

 myths, rites, and symbolism, extending to architecture and ornament, to details 

 of governnient, and to the every-day incidents and customs of national and 

 domestic life. In all of these we perceive a constant recurrence of the signs and 

 their correspondent numbers, drawn from the composite relations of twenty to 

 thirteen. 



