138 The Life Story of the Fish 



breathe through, the path of the air came to cross the path 

 of the food. For the air came in at the top and went out at 

 the bottom, whereas the food came in at the bottom and 

 went out at the top, as in the upper diagram in Figure 17. 

 If the fish had moved that air-bladder connection around 



5/omtfcA 



Figure 18. AIR AND FOOD SYSTEMS OF MAN 



to the top of the throat before the land animals branched 

 off from it, as in the lower diagram of Figure 17, it would 

 have been much more convenient for us. We might then 

 have succeeded in worldng out two separate passages, one 

 leading from the nose directly to the lungs, one from the 

 mouth directly to the stomach, with no trouble-breeding 

 interconnections. But it did not. The result is that the land 

 animals carried on that crisscross arrangement and never 

 modified it, and handed it on to us. Our food and our air 



