MORE ABOUT SUSPENDED ANIMATION 189 



tration of drugs, in the case of man and of higher animals, 

 are not due to that complete suspension of living changes 

 which we can produce, as I have here related, in certain 

 lower forms of life. These death-like trances are merely 

 cases of reduction of the living changes to a very low 

 degree. 1 



The bodies of all but the simplest animals and plants 

 are too large and too complex to survive the bursting and 

 disruptive action of extreme cold, due to the unequal 

 distribution of water within them and its irresistible 

 expansion when frozen. Their living mechanism is 

 broken, mechanically destroyed by this expansion. We 

 cannot hope to apply cold to man so as to produce, 

 "suspended animation." It is true that experiments are 

 on record in which fish and even frogs have survived 

 enclosure within a solid mass of ice by the freezing of the 

 water in which they were living. But careful experiments 

 are wanting which would demonstrate that these animals 

 were actually frozen through and through, and that either 

 fish or other cold-blooded animals can survive a thorough 

 solidification by freezing of their entire substance. Such 

 survival cannot be pronounced to be impossible, but it has 

 not been demonstrated in any cold-blooded animal — even 

 shell-fish or worm or polyp — let* alone a warm-blooded 

 mammal. It appears that, apart from disruptive effects, 

 the protoplasm of even very minute and simple organisms, 

 such as the Protozoa, does not in all kinds, even if in any, 

 survive exposure to great cold. The toleration of great 

 cold and return to living activity after thorough freezing 

 is, it appears, a special quality attained by the living 

 material of vegetable seeds and by many kinds of bacteria. 

 A similar special toleration of high temperatures, a good 

 deal short of the boiling point, but high enough to kill 



1 See the chapter on "Sleep," in my "Science from an Easy Chair," 

 Methuen, 1909. 



