436 THE WONDER OF LIFE 



lates about fifty. It is rather interesting that human 

 longevity is probably greatest of all among mammals, 

 with the possible exception of the large whales. 



As regards birds, more than one centenarian parrot has 

 been recorded, and the same age is credited to some birds 

 of prey. A raven of sixty-nine is authenticated, and an 

 eagle of sixty-eight. Herons, swans, and geese have a high 

 potential longevity, and an ostrich is said to be capable of 

 occasionally surviving for a term of thirty-five years. 

 A giant tortoise (Testudo gigantea) that was living near 

 Colombo in 1796, when Ceylon was first occupied by the 

 British, survived until 1894, so that it must have been more 

 than a centenarian. 



In the case of Man, we must clearly distinguish between 

 the average specific longevity, about thirty-four years in 

 Europe but happily raisable with decreasing infantile 

 mortality, improved sanitation, decreasing warfare, increas- 

 ing temperance and carefulness and the potential specific 

 longevity, which for the present race is normally between 

 seventy and one hundred years. There is no warrant for fix- 

 ing an ultimate limit, either for the past or the future. All 

 that we can scientifically say, is that there are few well- 

 established instances of a greater human longevity than 

 104 years. Sir George Cornewall Lewis did good service 

 (1862) in destructively criticizing numerous alleged cases of 

 centenarianism, the occurrence of which he at first regarded 

 as quite unproved, but even he finally admitted that men 

 do sometimes reach a hundred years, and that some have 

 reached one hundred and three or four. The famous 

 cases of Thomas Parr, Henry Jenkins, and the Countess 

 of Desmond, said to be 152, 169, and 140 respectively, were 

 ruled out of court by Mr. Thorns, who edited Notes and 



