LONGER LIVES.

Ohinemuri Gazette, Volume XXII, Issue 2794, 24 May 1911, Page 3

LONGER LIVES.

EVERY MAN A CENTEN-

ARIAN

■ " It is extremely doubtful if a really natural death ever does occur in any kind ot animal—including man," said Dr. Chalmers Mitchell, the secretary ot the Zoological Society, in the course oi a lecture on " Problems of animals in captivity,' which he delivered at the Royal Institution, London, recently. Dr. Mitchell supported MetchnikofFs theory that the changes of senility are the result of external accidents, of the poisons of various kinds of diseases, or of insanitary conditions. If. all these

causes were removed most animals, including ourselves, would attain very much greater ages than we do. To an animal living in a perfectly hygienic world, sheltered from all diseases, death would still eventually come, but as a result of the slow, gradual accumulation of waste matters of all kinds in the tis-

sues. Here are some of the interesting facts Dr. Mitchell stated :—"The potential 1 age of man should certainly be placed at well over ioo, and it is noticeable that centenarians are nowadays quite frequently heard of. The number of potential centenarians among animals is comparatively small. Among mammals we have only man, whales, and elephants, and among birds eagles and parrots. Humboldt told a story of a parrot so old that it spoke only in a forgotten tongue! Popular conceptions as to the age of animals are often based on such evidence. There is no relation

between size and potential longevity. A

canary lives almost as long as an ostrich, wh'le a parrot lives longer than an ostrich. Among reptiles there are wellestablished cases of turtles and tortoises living to 150 and 200 years. With fish we enter into the region of legend. Ihe old and dilapidated carp at Fontamebleau were at one time supposed to have reached an incredible age, but it has been shown that the basin was

cleaned out, and the carp were destroyed at the time of the Revolution, so that fixes the limit of their possible antiquity. There is also a story, which catinot be vouched for, that a carp caught in 1260, branded and thrown back into the sea, was recaught 260 years later ! A new and more satisfactory method of reckoning the lives of fishes is now being introduced. In connection with their ears

there is a structure consisting oi consecutive yearly deposits, which may be counted like the annual rings to tbe stem of a tree. Snails and sea molluscs are said to be able to live up to ibo

years, but the evidence is again doubtful. A sea anemone, however, kept in captivity in Edinburgh, was fully sjrovvn when pur into its tank, and only died as the result of an accident at the age of between sixty and seventy. The destruction of eggs, disease, changes of climate, starvation, and, above all, the attacks of enemies, account for the fact that few animals ever reach their potential ages." Dr Mitchell said that he has lately been observing the conditions of lite of animals living under captivity in our zoological gardens —over 20,000 cases of mammals and birds. He is en-

deavouring to ascertain whether we are harder on the animals than nature; whether on the whole we subject them to conditions that make their lite at least as long ; or whether we are simply killing them. It is entirely a new subject, on which we are only just feeling our way.