FEEDING OF CONTINTJOUS CROPS 153 



sufficient lime and sand for the making of the requisite 

 amount of mortar for 20 rods of a wall, and only 

 sufficient stone or bricks for 10 rods, then the wall- 

 building must cease when the 10 rods is erected, until 

 a further supply of building material is obtained. In 

 like manner a beast must have the proteins, oils, and 

 carbohydrates in certain proportions for its proper 

 nourishment. 



Now, if the builder has a sufficient supply of brick 

 or stone, but a deficiency of either sand or lime, he can 

 continue building an inferior type of wall — a dry wall 

 — ^without the lime. In like manner a beast fed on 

 albuminoids and carbohydrates, but without the third 

 ingredient, oil, can continue living and even increase 

 in weight, because the carbohydrates and fat are inter- 

 changeable. 



Again, a beast can be fed — ^but not economically — 

 on albuminoids and fat without carbohydrates. As 

 in the building of the dry wall, though, the results of 

 feeding on two foods are not as good as when the 

 three substances are available. 



Without either sand or lime a perfectly dry wall can 

 be erected with brick or stone alone, and in like manner 

 a beast can — ^again not economically — ^be fed for a 

 time on pure albuminoids. This is because the albumi- 

 noids can fulfil the functions of both fat and carbo- 

 hydrates, but the point to be especially remembered is 



that NEITHER FAT NOR CARBOHYDRATES CAN BE CON- 

 VERTED INTO OR FULFIL THE FUNCTIONS OF ALBUMI- 

 NOIDS. In other words, no matter how liberally a beast 

 be fed on fat or carbohydrates, in the absence of 

 albuminoids, the beast will die. 



THE ALBUMINOID RATIO 



The fat and carbohydrates in a food are often 

 spoken of as the non-albuminous portion, and the 

 albuminoids or protein as the albuminous. 



