CAGES 



341 



and then push it on gently and steadily until the en- 

 tire bulb and part of the stem, as far as the constric- 

 tion, have passed into the rectum. Three to five min- 

 utes later, the time varying of course with the sensi- 

 bility of the thermometer used, withdraw the instru- 

 ment and take the reading. The thermometers em- 



FIG. 167. Mouse scales 



ployed for recording temperature should be verified 

 from time to time by comparision with a standard 

 Kew certified Thermometer kept in the laboratory 

 for that purpose. 



Cages. During the period which elapses between 

 inoculation and death, or complete recovery, the ex- 

 perimental animals must be kept in suitable recep- 

 tacles which can easily be kept clean and readily 

 disinfected. 



The mouse is usually stored in a glass jar (Fig. 168) 



