The Biology of Senescence 



course, not the first occasion in biology when a procedure which 

 was attempted with enthusiasm and abandoned in disgust has 

 come back into useful currency after a period of meditation and 

 study. An equally productive field may well be that of organ 

 culture, initiated by Carrel, but still comparatively little used. 

 Apart from such specialized investigations, serious progress 

 depends on the cultivation of general awareness among bio- 

 logists of the importance of prolonging their study of every 

 animal into the senile period, of collecting and publishing life- 

 tables, especially for cold-blooded vertebrates under good 

 laboratory conditions, and of seeking confirmatory evidence of 

 the distribution of senescence in phylogeny. A few years of 

 propaganda to zoologists in training might bring in a rich 

 factual harvest later. Much modern research into ageing tends 

 to be desultory, although the single subjects with which it deals 

 are important in themselves. We ought to try to devise critical 

 experiments, and if we destroy more hypotheses than we demon- 

 strate, this is a subject which can well stand such treatment in 

 contrast to the speculation which has gone before. The most 

 desirable condition for progress in gerontology at the moment 

 is that the exact nature and scope of the problems raised by 

 senescence should be understood, and the possibility of new 

 experimental evidence borne in mind, during the planning and 

 assessment of all biological research, even when it is primarily 

 directed to other objects. Senescence, like Mount Everest, 

 challenges our ingenuity by the fact that it is there, and the 

 focusing of our attention on it is unlikely to be fruitless. 



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