226 BACTERIOLOGY. 



no bearing upon the general condition of the animal, 

 but are probably due to transient causes, such as over- 

 feeding or scarcity of food, improper feeding, lack of 

 exercise, excitement, fright, etc. 



The accompanying charts (Figs. 49, 50, 51, 52) will 

 serve to illustrate some of these points. The animals, 

 two rabbits and two guinea-pigs, were taken at random 

 from among the 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 grammes 

 of green food (cabbage and turnips) daily, and the 

 guinea-pigs 30 grammes 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 grain (oats 

 and corn). By reference to the charts sudden diurnal 

 fluctuations in weight will be observed that do not 

 correspond 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 recovered 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 the recorded temperatures 

 one sees the peculiar fluctuations mentioned. To just 

 what they are due it is impossible to say. It is mani- 

 fest that the normal temperature of these animals, if we 

 can speak of a normal temperature for animals present- 

 ing such fluctuations, is about a degree or more, Centi- 

 grade, higher than that of human beings. The animals 



