SUBCUTANEOUS INOCULATION OF ANIMALS 249 



normal animals when confined in cages and fed regularly 

 often present very striking temporary gains and losses in 

 weight, often amounting to 50 or 100 grams in twenty-four 

 hours, even in animals whose total weight may not exceed 

 500 or 600 grams; similarly unexplainable rises and falls 

 of temperature, often as much as a degree from one day to 

 another, are seen. Such fluctuations have apparently no 

 bearing upon the general condition of the animal, but are 

 probably due to transient causes, such as overfeeding or 

 scarcity of food, improper feeding, lack of exercise, excite- 

 ment, fright, etc. 



The accompanying charts (Figs. 47, 48, 49, 50) will serve 

 to illustrate some of these points. The animals, two rabbits 

 and two guinea-pigs, were taken at random from among 

 stock animals and placed each in a clean cage, the kind used 

 for animals under experiment, and kept under as good 

 general conditions as possible. For the first week the rabbits 

 received each 100 grams of green food (cabbage and turnips) 

 daily, and the guinea-pigs 30 grams each of the same food. 

 During the second week this daily amount of food was 

 doubled; during the third week it was quadrupled; and for 

 the fourth and fifth weeks they each received an excess of 

 food daily, consisting of green vegetables and grains (oats 

 and corn). By reference to the charts sudden diurnal 

 fluctuations in weight will be observed that do not corre- 

 spond in all instances with scarcity or sufficiency of food. 

 With the rabbits there is a gradual loss of weight with the 

 smaller amounts of food, which losses are not totally re- 

 covered as the food is increased. With the guinea-pigs there 

 is likewise at first a loss; but after a short time the weight 

 remains tolerably constant, and is not so conspicuously 

 affected by the increase in food as one might expect. From 



