DIFFERENCE IN FOOD. 169 



advantages they become larger than those 

 which have them not. The same thing hap- 

 pens in, so to say, human ponds ; for in 

 large cities we find that the babies and young 

 children who are well fed and live in good air 

 are much stronger and healthier ah, and for 

 the most part larger too, than those born and 

 bred in crowded courts and back passages, 

 and who feed on red herrings and tea rather 

 than on butchers' meat and beer. Take a 

 given number of children from a given large 

 city, say a hundred of the same age, and put 

 them side by side. I doubt not that we 

 should be able to pick out three specimens 

 from among them whose full-length photo- 

 graphs, if grouped together, shall show as 

 much difference as do the drawings of the 

 three fish now before the reader. A naturally 



