INORGANIC FOODS. 

 RABBITS, SERIES II. 



385 



A glance at these tables shows distinctly that shortly after birth a con- 

 siderable amount of the iron is present in some other form than hemo- 

 globin. This amount of iron diminishes rapidly during the first few 

 days after birth, and is evidently transformed into hemoglobin. After 

 about the sixth day from birth, the amount of iron not present as hemo- 

 globin, per 1000 grams of the animal's weight, remains fairly constant. 

 Inasmuch as the animal is constantly gaining in weight during this period, 

 it is . evident that iron must be continuously deposited in the tissues. 

 This iron comes from the milk. On the other hand, the absolute amount 

 of hemoglobin likewise increases. At all events, the above values show 

 the minimum amount of iron which is in the tissues of the rabbit and 

 which is held there most tenaciously. From this point of view it is not 

 difficult to understand why the new-born animal is provided with so 

 great an amount of stored-up iron. During the first few days consider- 

 able hemoglobin is formed, and, if there were not this supply of iron, it 

 would be necessary for the milk to contain much more iron than usual in 

 order to satisfy the requirement. A study of the cells of the milk-glands, 

 however, shows that on the whole they are nearly fitted to furnish a quite 

 definite secretion. The task of the cells in satisfying the demands of the 

 young organism is, therefore, lightened by the fact that the offspring 

 already has this extra supply of iron available. As Hugonnenq l has 

 shown in the case of the human foetus, this storing up of iron takes place 

 chiefly during the last three months before birth. There is nothing 

 whatever to indicate that the iron is stored up merely because it is a 

 substance difficult for the young organism to absorb and assimilate. 



1 Compt. rend. 128, 1054 (1899). 



