180 SECRETS OF ANIMAL LIFE 



Bernard's view that vital activity is wholly sus- 

 pended, for why should there be a limit, if this be 

 so? It is quite likely, however, that the limit 

 is determined not by the potency of the essential 

 protoplasm, but by the endurance of the colloidal 

 substratum the furnishings of the chemical 

 laboratory. The spring of the stopped watch might 

 in the course of time undergo some molecular change 

 which robbed it of its elasticity, so that no shake 

 would set the works going again. Something analo- 

 gous may occur in the desiccated organism. 



The recent experiments clearly show that subjec- 

 tion to conditions utterly hostile to the persistence 

 of the most attenuated of vital processes or metabo- 

 lism is not necessarily fatal. Macquenne kept 

 parsnip seeds for two years in a vacuum, and 

 made them as dry as dry could be, yet they were 

 still able to germinate. Indeed, they retained their 

 sprouting power for a much longer time than con- 

 trol seeds kept in the open air. The same conclusion 

 is suggested by similar experiments made by Bec- 

 querel and also by the results of subjecting seeds 

 to very low temperatures. Using the refrigerat- 

 ing laboratory or " cryogen " of M. Kammerlingh 

 Onnes at Leyden, he subjected naked seeds of 

 lucerne, mustard, and wheat for three weeks to the 

 temperature of liquid air, and then for seventy- 

 seven hours to that of liquid hydrogen at 250 

 below zero. The seeds were then put into a vacuum 

 for a year. Under the combined influence of low 

 temperature arid desiccation, the protoplasm lost 



