24 EFFECT OF DIET ON THE ALBINO RAT 



A glance at Tables VIII and IX shows that, with the exception 

 of the exercised vegetarian female, the exercised rats reach their maxi- 

 mum weight at an older age than the control rats, regardless of the diet. 

 In Table X these facts are in a more accessible form. It shows the 

 individual weights and the age of each rat, and the average weights 

 and ages of each sex in each group, at the beginning of the experiment, 

 as the maximum weight, and at death. As already stated, the average 

 weights of the young were about as uniform as could be gotten. When 

 the maximum weights are considered a marked contrast is noted. In 

 every case the average weight of each sex is decidedly in favor of the 

 omnivorous rats. 



Considering the exercised rats in regard to the maximum weights 

 and weights at death, we find the following ratios: 



MAXIMUM WT. AT DEATH 



Omnivorous male to vegetarian male i .8 : i 2.2 : i 



Omnivorous females to vegetarian females 1.42 : i 1.36 : i 



In regard to the control rats the following ratios were found : 



MAXIMUM WT. AT DEATH 



Omnivorous male to vegetarian male 1.64 : i 1.9 : i 



Omnivorous female to vegetarian female. . 1.22 : i .9:1 



This last ratio is not reliable, as the control female had to be killed 

 on account of sickness. There is no doubt had it been normal it would 

 have reached a much heavier weight, since other omnivorous females 

 did not reach their maximum weight until a much later age. 



In regard to growth, we must conclude that the data is decidedly 

 in favor of the omnivorous rats and against the vegetarians. 



The appearance and attitude of the two groups is also in marked 

 contrast. Figures 14, 15, 16 and 17 are photographs of eight of these 

 rats, all being of the same age. Those on the left of each figure are 

 omnivorous rats; those on the right are vegetarians. Figure 14 repre- 

 sents females. The other three figures are of males. 



These photographs show the marked difference in appearance and 

 attitude referred to above. The vegetarians were emaciated and skinny. 

 Their back arched and more or less stiffened. The fur was harsh and 

 rufHed, and the tail and nose inclined to be more or less covered with 

 dry scale and sores. The attitude presented extreme lassitude and 

 indifference. They remained in a crouched position most of the time, 

 their legs appearing too weak to support their weight for only a short 

 while. They lacked energy and would stay "put" when placed ready 

 for photographing. 



