INHERITANCE OF ACQUIRED CHARACTERS 165 



155. Food supply and body changes. All the evi- 

 dence available points to the fact that the domestic ani- 

 mals have inherited not only a tendency to reach a cer- 

 tain size and form, Hut that they have inherited a strong 

 tendency to attain a given size at a certain age. Thus, 

 in these investigations at the Missouri Experiment 

 Station, there is evidence to show that the animal organ- 

 ism makes desperate efforts to grow, even when the food 

 supply is greatly limited. In one case a calf nine-and- 

 one-half months old was fed a limited ration which 

 resulted in a loss of weight amounting to 82 pounds in 

 six months. During the same period this animal in- 

 creased 8.1 per cent in height and 14 J per cent in length 

 of head. 1 



156. Influence of limited food supply from birth. 

 The amount of food supplied to a growing animal in a 

 large measure determines not only its ultimate develop- 

 ment, but the rate at which the animals grow. In another 

 investigation at the Missouri Experiment Station, 2 three 

 animals were fed a full ration, a medium ration and a 

 scant ration, respectively. Animal number 527 (Plate VII, 

 upper) given a full ration, increased in weight rapidly, and 

 at the end of 789 days weighed 1453 pounds. Animal 559 

 (Plate VIII, lower), given a medium ration intended to 

 produce a normal growth, but not a fattening ration, at 

 the end of 780 days weighed 813 pounds. Animal 551 

 (Plate VII, lower) , given a scant ration, weighed at 777 days 

 512 pounds. It is, of course, possible that in these experi- 

 ments the differences in body weight may be due to the 



1 Waters, Proceedings of the Society for the Promotion of Agri- 

 cultural Science, 1908. 



2 Waters and P. F. Trowbridge, Unpublished Data of the 

 Missouri Experiment Station. 



