BIOLOGY 



Royds. This means that the animals must be capable of 

 remaining frozen for years, possibly for many years, 

 without being killed. Though enclosed in the ice, there 

 was no means of knowing how low temperatures they 

 could endure, for the ice in the lakes might never be so 

 cold as the air. 



A few simple experiments were carried out with the 

 object of finding what degree of cold they could survive. 

 Afterwards the experiments were extended in other direc- 

 tions; they were heated, they were immersed in various 

 saline mixtures; in short, they were submitted to various 

 tests such as they might be exposed to in nature. It must 

 be admitted that we did not ascertain what limits of tem- 

 perature they could endure. We only know that they live 

 at a certain low temperature ; the Antarctic was not cold 

 enough to show us any temperature at which they die. 



From facts previously ascertained we may predicate 

 approximately what is the limit at the other end of the 

 scale. Animal protoplasm is known to coagulate at a 

 point well below the boiling-point of water. As the 

 Antarctic was not cold enough, it was intended to use the 

 resources of civilisation in order to get greater cold, by 

 the use of liquid air. Unfortunately, the animals had to 

 be subjected for some weeks to an almost tropical tem- 

 perature, and were found to be all dead when they reached 

 Sydney.* 



Tenacity of Life 



To test the degree of cold which they could stand blocks 

 of ice were cut from the lakes and exposed to the air in 

 the coldest weather of the whole winter. By boring into 

 the centre of the blocks we found that they were as cold 



* Since this was written, examination of the rotifers in London 

 (in September 1909) has shown that they are still living. 



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