290 THE LIFE OF A BIRD. 



understood that it is heat which gives life to the 

 little germ ? Heat is equally necessary to kindle 

 the spark of life in the death-like pupa state of 

 the insect, or in the tiny germ contained within 

 its egg. Nor is heat less essential to the quick- 

 ening of life in the seed buried in the soil. Yet 

 in neither of these instances can it be for a moment 

 considered that heat is any thing more than a 

 necessary condition. Heat gives not life to the 

 germ. The life is in itself; but it cannot be 

 developed without the requisite degree of heat for 

 that purpose. In the case of plants, it appears 

 that the chemical rays of sunlight are almost as 

 essential as those of heat. As yet, we are not 

 able to say the same with respect to eggs. But 

 in every case, heat, or the actinic ray, or both 

 combined, or electricity, or any other physical 

 agencies, are not the cause of life. Life is the gift 

 of God, whether to the seed or egg, and myste- 

 riously lies dormant in the organized particles 

 until favouring circumstances present themselves 

 for its development. How mysterious this ap- 

 pears ; and what a lesson of humility and 

 reverence is impressed on the mind which per- 

 ceives itself unable to comprehend the com- 



