THE BREEDING OF MICE IN LABORATORIES 51 



tive measures. However, should the infestation persist, the 

 mice may be individually caught by the tail, dipped in a 

 warm, very dilute solution of stock-dip, and allowed to dry 

 in a warm place. If metal cages are employed, the nest and 

 food may be removed and the whole cage dipped, mice and 

 all. We have found Parke Davis and Company's Kreso-Dip 

 satisfactory for this purpose. 



Mice are occasionally attacked by a white fungus which 

 grows upon their ears. It is difficult to eradicate and hence 

 if the affected animal may be spared it should be killed. If 

 the fungus affects only the tip of an ear when discovered, it 

 may frequently be eliminated by clipping off the ear below 

 the affected region. Adult mouse ears seldom bleed when 

 snapped off, but if they should, a little sodium subsulphate 

 powder will quickly stop the flow. 



Mice sometimes harbor a tapeworm for which the cat 

 serves as definitive host. Accordingly, it is advisable to 

 exclude all cats from the mouse room. There are other more 

 obvious reasons why cats are undesirable tenants of a 

 murarium. 



Diseases. Some strains of fancy mice are affected with 

 hereditary tumors. Those involving the mamma? of the 

 female are the most common. If a tumorous female is very 

 valuable, occasionally a single litter of mice may be pro- 

 cured from her after surgical removal of the growth. As a 

 general practice animals bearing tumors should be discarded 

 as the results seldom justify the efforts to save them. 



Mice are susceptible to a number of non-specific organism- 

 borne diseases {171, 133), such as surra {Trypanosoma evansi), 

 apoplectic septicemia, fakosis {Micrococcus caprinus), fowl 

 cholera {Bacterium cholerce gallinarum), trichosis {Trichinella 

 spiralis), the disease caused by Bacillus piliformis, sarcospiri- 

 diosis, botryomycosis, and coccidiosis. These diseases will 

 seldom be encountered in a well-kept mouse colony, and 

 hence a mere mention of them will suffice here. 



By far the worst disease among laboratory mice is para- 

 typhoid {175) (often known as diarrhoea) caused by Bacillus 



