84 Scientific Proceedings, Royal Dublin Society. 



very slow breeders. Monkey's reproduce slowly, and are long- 

 lived.^ In the vegetable kingdom it appears on the whole as if 

 a similar order prevailed. Annuals reproduce themselves profusely, 

 while the larger and longer-lived shrubs and trees spread slowly 

 in comparison. 



I have not in the foregoing specially referred to climatological 

 death. Death through the periodic rigour of the inanimate environ- 

 ment calls forth phenomena very different from death introduced 

 Or favoured by competition. But a multiplicity of effects inter- 

 mediate in nature occur. Organisms will, for example, learn to 

 meet very rigorous conditions if slowly introduced, and not 

 permanent. A transitory period of want can be tided over by 

 contrivance. The lily withdrawing its vital forces into the bulb 

 protected from the greatest extremity of rigour by seclusion in the 

 earth, the trance of the hibernating animal are instances of such 

 contrivances. 



But there are organisms whose life-wave truly takes up the 

 periodicity of the earth in its orbit. Thus the smaller animals and 

 plants, possessing less resources in themselves, die at the approach 

 of winter, propagating themselves by units which, whether egg or 

 seed, undergo a period of quiescence during the season of want. 

 In these quiescent units the energy of the organism is potential, 

 and the time- energy function is in abeyance. This condition is, 

 perhaps, foreshadowed in the encystment of the amseba in re- 

 sistance to drought. In the case of hibernation the time-energy 

 function seems maintained at a loss of potential by the organism, 

 a diminished vital consumption of energy being carried on at the 

 expense of the stored energy of the tissues. Soo, too, even among 

 the largest organisms there will be a diminution of activity 

 periodically inspired by climatological conditions. Thus, wholly 

 or in part, the activity of organisms is recurrently affected by the 

 great energy-tides set up by the earth's orbital motion. 



Similarly in the ] phenomenon of sleep the organism responds 

 to the earth's axial periodicity, for in the interval of night a 

 period of impoverishment has to be endured. Thus the diurnal 



^ I kept a small pet monkey for twenty years. She died but recently, not from old age, 

 but from cold and dysentery. When she came into my possession she was an adult, and 

 probably some years old. See "The Duration of Life " ("Weismann) for much infor- 

 mation on this subject. 



