and death ensues.



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Generation is the initial participation, mediated by warm substance,

in the nutritive soul, and life is the maintenance of this

participation. Youth is the period of the growth of the primary

organ of refrigeration, old age of its decay, while the intervening

time is the prime of life.

A violent death or dissolution consists in the extinction or

exhaustion of the vital heat (for either of these may cause

dissolution), while natural death is the exhaustion of the heat

owing to lapse of time, and occurring at the end of life. In plants

this is to wither, in animals to die. Death, in old age, is the

exhaustion due to inability on the part of the organ, owing to old

age, to produce refrigeration. This then is our account of

generation and life and death, and the reason for their occurrence

in animals.



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It is hence also clear why respiring animals are suffocated in water

and fishes in air. For it is by water in the latter class, by air in

the former that refrigeration is effected, and either of these means

of performing the function is removed by a change of environment.

There is also to be explained in either case the cause of the

cause of the motion of the gills and of the lungs, the rise and fall

of which effects the admission and expulsion of the breath or of

water. The following, moreover, is the manner of the constitution of

the organ.



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