490 [Assembly 



The larvse of insects are found to be equally tenacious of the 

 vital principle. Lister, Bonnet, and others, are said to have 

 found caterpillars so frozen that when dropped into a glass they 

 chinked like stones; but that they, nevertheless, revived on being 

 brought into warm quarte<rs. 



Spailanzani discovered that exposure to a temperature of 38°, 

 or even 36^, did not destroy the fertility of the ova of silk 

 worms. 



Sir John Ross, on his voyage, placed thirty larvae of the Laria 

 Rossia in a bus, and exposed them three months to the winter 

 temperature. On bringing them into his cabin, every one of them 

 returned to life and crawled about. They were again exposed, 

 and instantly became re-frozen. After a week they were brought 

 into the cabin and twenty-three returned to life. These were 

 again exposed and re-frozen, and, after remaining solid for anoth- 

 er week, eleven of them recovered when brought into the cabin. 

 They were a fom-th time frozen and brought into the cabin, when 

 two only came to life. 



Learned men say, that these facts indicate that the power of 

 revification after the complete congelation of the fluids, is con- 

 fined to animals in which the function of calorification is imper- 

 fectly performed, and in which all the vital processes are ob- 

 scurely manifested. 



It is c^rfaiii tiiat the functions of vitality are much more 

 obscurely performe«l in plants, therefore they should be endowed 

 with a like power of resisting the effects of freezing. Still, sci- 

 -eutific men say that complete solidification of the fluids of a 

 plant necessarily result in its destruction. 



Professor Henslow seems to think that the chief protection 

 .against the sap freezing in the trunks of trees, is the circumstance 

 of its being contained in extremely minute vesicles and capillary 

 vessels. Water will resist a temperature of 16^ Fahrenheit under 

 similar circumstances, and all viscid fluids are still more difficult 

 to freeze than water. 



