858 LONGEVITY foxes, hares, rabbits, from seven to ten years ; and dogs and pigs from fifteen to twenty years Certain general state ments may be made, which do not deserve to be termed laws, but which briefly express relations that undoubtedly exist in many cases between the degree of longevity enjoyed by any species of animal and the conditions of its existence. 1. A relation can often be traced between the duration of life and the time of the development of the animal in utero. To this statement there are many exceptions, as will be apparent from the following table, in which the periods of gestation are given on the authority of Professor Owen (Comp. Anat. and Pliys. of Vertebrates, vol iii.): 4-, C O -J o- C o c oi Name. 5 ~ >. Longevity in Years. Name. .=. jf ^ Longevity in Years. 0.5 o.s r 9 100 150 10 Giraffe 440 Pirr 120 15 20 Mare and Ass 330 30-40 Marmoset 120 Cow 286 15 20 105 Human Being 280 80-100 Wolf, Jackal, Dog 63 15-20 280 30 Cat 5G 15 9 Red Deer ) Fallow Deer .... f 245 30 Bat ( Vesper tilio noctula) j 40 Xot known. Hippopotamus .... 234 Kot known. Kangaroo 38 Vot known. In the case of birds no relation of this kind can be discovered. For times of incubation of many birds see Owen, op. cit., vol. ii. p. 257. 2. It would appear that the sooner a being attains maturity the sooner it propagates, and the shorter will be the duration of its life. The reproductive act may be regarded as the culminating act of the organism, requiring the highest degree of vitality, and involving the largest expenditure of energy. This act will therefore be performed when the organism has reached maturity; in some cases the animal reaches maturity late, in other cases early ; but in all the epoch of maturity may be taken as about a fifth part of the whole duration of life. Thus the elephant and the human being do not reach maturity till say the twentieth year, and the period of longevity is about a hundred years ; the horse, ass, and bull are mature in the third or fourth year, and live from fifteen to twenty years; sheep come to maturity in the second year, and live from eight to ten years; whilst rabbits and guinea pigs are mature within one year, and live only from four to five years. Here again there are exceptions, as, for example, the cat is mature before the end of the first year, and still it may live to the age of twenty years. Much information is still required on these points before a law can be formulated. The question of longevity, however, probably presents the greatest interest in its relation to man. It is still a popular belief that the earliest inhabitants of the world possessed an incredible strength, were of an enormous size, and lived to a very great age ; and the ages of the patriarchs before the flood are often taken literally, although the con ditions making such long lives possible are at variance with those of human existence at the present day. In ancient history there are instances given of heroes who attained the age of several hundred years, but these must be regarded as mythical. For an interesting account of these, see Huf eland s Art of Prolonging Life, p. 62 sq. The following are a few instances of extreme longevity which have been placed on record : Margaret Patten, 137; the countess of Desmond, 145; Thomas Parr, 152; Thomas Damme, 154; John Rovin, 172; and Peter Torton, 185. There can be little doubt that the ages of these persons have been much exaggerated. They lived at a time when no accurate chronological records were kept, and when it was the habit to fix the dates of occur rences by comparing them in the memory with other events believed to have happened about the same time. Thus there were many sources of fallacy, although the narrators no doubt believed their statements to be quite accurate. Still these were instances of prolongation of human life far beyond the usual limits, and there is no reason fr doubting that they all lived till they were upwards of a hundred years of age. Perhaps the best authenticated instance of this kind is that of the famous Thomas Parr of Shropshire. "He was a poor far mer s servant, and obliged to maintain himself by daily labour. When above one hundred and twenty years of age he married a widow for his second wife, who lived with him twelve years, and who asserted that during that time he never betrayed any signs of infirmity of age. Till his one hundred and thirtieth year he per formed all his usual work, and was accustomed even to thresh. Some years be/ore his death his eyes and memory began to fail, but his hearing and senses continued sound to the last. In his one hundred and hfty-secoiid year his fame had reached London ; and, as the king was desirous of seeing so great a rarity, he was induced to take a journey thither. This, in all probability, shortened his existence, which he otherwise might have preserved some years longer ; for he was treated at court in so royal a manner, and his mode, of living was so totally changed that he died soon after, at London, in. 1635. He was one hundred and fifty-two years and nine months old, and had lived under nine kings of England. What was most remarkable in regard to this man is that, when his body was opened by Dr Harvey (the discoverer of the circulation of the blood), his internal organs were found to be in the most perfect state, nor was the least symptom of decay to be discovered in them. His cartilages even were not ossified, as is the case in all old people. The smallest cause of death had not yet settled in his body ; and he died merely of a plethora, because he had been too well treated." Hufeland, p. 71. The late Sir George Cornewall Lewis attempted to show that all such narratives were so inaccurate as to reduce the ages of the parties to something under a hundred years, and he was disposed to think that there had been no instance of a human being attaining the age of a hundred years. But subsequent cases have shown that a few have attained that great age. In these cases the evidence has not been of a collateral kind, nor has it depended on human memory, but it has been established by written records. Scarcely a year passes without instances occurring in which the evidence that the deceased attained a hundred years cannot be controverted, and there is no doubt that, when a sufficient time from the beginning of the system of registration of births has elapsed, such cases will be more common. The average duration of life in Europe is about thirty- four years. It oscillates between 28 18 j-ears (Prussia) and 39 8 years (Schleswig-Holstein, Lauenburg). In Naples it is quoted at 31 65 years. This falls far short of the possible longevity, a circumstance chiefly to be accounted for by the great mortality in the early years of life. According to De Quatrefages, the duration of life is almost universally the same amongst the best known peoples. Laplanders live to a great age, men of from seventy to ninety years of age being common among them. The American Indians have apparently as long a life, on the average, as the white men living in the san.o locality. It would appear to be the same in the case of the negro. Prichard quotes from an official document of the State of New Jersey ; showing that the census gave one negro centenarian in the 1000, but only one white centenarian in 150,000 ; on the other hand, the negro of the Senegal ages early, and does not live long. In his native place he is exposed to unhealthy influences which tell upon him, although he resists the bad effects of these longer and better than the white man ; but when he is transplanted to America he enjoys a longer life. The manner of life and nature of the occupation, apart from hereditary and special causes, have a most important influence on the duration of life. Few emperors or kings have attained the age of eighty ; and, of more than three hundred popes, only six have exceeded the age of eighty. It
