The Biology of Senescence 



the general biology of ageing has appeared since, although its 

 evolutionary basis has been discussed (Haldane, 1941; Meda- 

 war, 1952). The decline in abstract speculation about old age 

 is probably in itself a very good augury for research. Much of 

 the previous published matter abundantly justified the view of 

 Bacon that 'the method of discovery and proof whereby the 

 most general principles are first established, and then inter- 

 mediate axioms are tried and proved by them, is the parent of 

 error and the curse of all science'. 



In later work, the relation between growth-cessation and 

 ageing has been generalized to cover the senescence of all 

 kinds of organisms which have a fixed life span, such as the 

 rotifers (Lansing, 1947a) in which the mechanism of ageing 

 may be, and very probably is, quite unlike that which occurs 

 in vertebrates. The real importance of Bidder's suggestions 

 lies, however, in the possibility they indicate that mammalian 

 senescence may be a close evolutionary correlate of certain 

 investigable mechanisms, such as homoeothermy, which have 

 evolved with it. The probing of this possibility belongs to the 

 future. 



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