DEATH 399 



mals) are not so long-lived as many have supposed. Records 

 have not been carefully kept, but it is probable that man is the 

 longest-lived of any of the mammals. Even in man, authentic 

 records of centenarians are very few. As Young (1905) has pointed 

 out, before one can be absolutely sure of an age record, he must 

 have the documentary proof of the following critical points: 



1. Date of birth. 



2. Date of death. 



3. Proof that the two records are of the same person. 



4. The marriage date and any other records which aid in es- 

 tablishing identity; this is especially valuable in the case of women. 



Young considers the third point the most important. It is 

 very easy to confuse the birth and death records of two different 

 people of the same name, and such confused records have often 

 been used to substantiate the claims of excessive longevity. After 

 examining nearly a million records, insurance tables, etc., he 

 found only thirty authentic cases of people who had died when 

 over 100 years old (not including the cases mentioned in the 

 Bible). Of these, twenty-one were women and nine were men. 

 The most extreme case of longevity on record was that of a per- 

 son who attained the age of 110 years, 10.5 months. When this 

 is compared with the records of the deaths in the United States 

 for 1916, when 649 deaths over 100 years were recorded (317 

 white and 332 black), the necessity for the documentary proof 

 required by Young becomes apparent. No records should be be- 

 lieved without the corresponding substantiating proof. 



2. There is no relationship between average length of life of a 

 species of animal and any other fact in its life history, structure, 

 or physiology. It has been suggested by Weismann (1891) that 

 the larger an animal the longer its life, but there are so many ex- 

 ceptions to this rule that it has no value whatever. Man is one 

 of the longest-lived of the mammals and yet he is by no means 

 among the largest. 



In plants there is a kind of correlation between the size of the 

 individual and the longevity, owing to the indefinite habit of 

 growth possessed by plants. The annuals are herbaceous and 

 seldom attain in the one growing season a very large size. The 

 perennials, which include the shrubs and trees, are the longest- 

 lived of plants and the largest, but the peculiar plant habit of 

 local indefinite growth mentioned above may explain here the 



