PLATE 2 



EXPLANATION OF FIGURES 



3 Photomicrograph of spleen of Spermophile 117, a male captured in the 

 spring of 1915. It had been torpid for thirtj'-five days. Had access to food. 

 Killed January 10, 1916, by bleeding. At this time it weighed 165 grams and 

 the rectal temperature was 14°C. 



4 Photomicrograph of spleen of Spermophile 266, a female captured in June, 

 1914. It hibernated when kept in the cold during the winter of 1914-1915. Placed 

 in hibernating room and food withdrawn the latter part of September, 1915. 

 Killed January 27, 1916, after hibernating about one hundred and twenty-five 

 days. Rectal temperature at time of death 17°C. Daily observations were not 

 made. The spleen is practically normal. 



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