APPENDIX IV. LONGEVITY OF ANIMALS 



A UGUST WEISMANN in his essay on Lebensdauer has col- 

 ** lected many data in regard to the longevity of animals. 

 It is by far the best compilation of the sort known to me. 



Mr. F. A. Lucas, Curator of the Brooklyn Museum, has given 

 me some additional facts, and by his courtesy I am allowed to 

 publish the following quotation from a letter which he addressed 

 to me on November 27, 1907: 



"So far as we know the Aldabra tortoises have reached the 

 greatest age from ninety to one hundred and fifty years. Of 

 this we may be positive. Carp 'are said' 'to have lived over a 

 hundred years,' and I should not be surprised if this were true. 

 I doubt much if any mammals attain such an age. Until I went 

 to Newfoundland in 1903 I had credited the whale with living to 

 a very great age, but my examination of the many specimens I 

 saw there leads me to doubt this. I discussed the matter a little 

 in Nature and in Science, but the gist of the matter is this if 

 whales lived indefinitely there should be an indefinite number of 

 sizes, whereas the animals fall into comparatively few groups as 

 regards size, and I now doubt if the whale lives much more than 

 twenty-five years, though this is a mere guess. Observations 

 made on the Pribilof Islands during the past ten years show that 

 the fur seals probably do not reach the age of twenty years with 

 which they have been credited and the fur seal is a fairly large 

 mammal. Even in regard to reptiles, which have been supposed 

 to grow very slowly and almost indefinitely, recent observations 

 have shown that the Galapagos tortoise and our own alligator 

 may grow quite rapidly." 



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