18 WONDERS OF ORGANIC LIFE. 



their temporary approximation to each other, or 

 in some alteration which we cannot appreciate, 

 but which enables them to perform the function 

 of muscles. We have said that the coagulation 

 of the blood is the result of its death, or the mode 

 in which it parts with its vitality. But in the case 

 of animals struck dead by lightning, the blood 

 does not coagulate, the muscles do not become 

 rigid, and decomposition rapidly ensues. Here 

 the vitality of the blood is instantaneously 

 destroyed ; no space of time being allowed for it 

 to exhibit the ordinary phenomena attending its 

 gradual death. Of the changes which the blood 

 undergoes in various diseases, or disturbances of 

 the organic functions from unnumbered causes, 

 it is not here our place to speak ; our aim is solely 

 to give an explanation of the composition of the 

 vital fluid, of which many persons are ignorant. 

 From the blood the system is nourished and 

 repaired ; perspiration and all the secretions 

 tend to its decrease ; hence it continually needs 

 recruiting. This is effected by the reception 

 and assimilation of matter which had once 

 lived under an animal or vegetable form, and 

 which having died is now to live again, but 

 also again to die, and perchance enter into 

 another condition of organization. 



The process termed digestion, by which the 

 blood is recruited, remains to be briefly de- 

 tailed. All animals do not crush, mince, or 

 masticate the food previously to transferring it 

 to the stomach ; reptiles and fishes swallow 

 their prey whole, and the lower animals engulf 



