NATURAL THEOLOGY. 275 



But, forasmuch as the action of the air upon 

 the blood in the lungs appears to be necessary to 

 the perfect concoction of that fluid, i. e. to the life 

 and health of the animal, (otherwise the shortest 

 route might still be the best,) how comes it to 

 pass that the fcetus lives, and grows, and thrives 

 without it ? The answer is, that the blood of the 

 fcetus is the mother's ; that it has undergone that 

 action in her habit ; that one pair of lungs serves 

 for both. When the animals are separated a new 

 necessity arises ; and to meet this necessity as soon 

 as it occurs an organization is prepared. It is 

 ready for its purpose ; it only waits for the atmo- 

 sphere ; it begins to play the moment the air is 

 admitted to it.''^ 



^ Does not the whole condition of the embryon go to this argu- 

 ment ? At first there is a mere jelly, or what appears as such ; a 

 little farther advanced, and there are bones, and muscles, and 

 nerves. But these lie quite inactive for a long term ; the nerve 

 excites to no action ; the muscles do not move ,• the joints are not 

 exercised, they are perfected slowly. The period of full develope- 

 ment is not arrived ; they have not yet their stimulus to activity. 

 The whole then is in a state of preparation. Conduit pipes with- 

 out their fluids, glands and ducts without their secretions, sensi- 

 bilities dormant, and a mechanism quite inoperative ; a whole 

 animal system beautifully contrived, but only in "prospective 

 contrivance." 



