PLATE 1 



EXPLANATION OF FIGURES 



1 Photomicrograph of spleen of Spermophile 260, a female captured in the 

 spring of 1915. It had been torpid continuously for fifteen days, although it 

 had hibernated for a short time also earlier in the season. Did not have access 

 to food. Killed January 1, 1916, by bleeding. At this time it weighed 85 grams 

 and the rectal temperature was 12°C. The photomicrograph shows the marked 

 distention of the venous sinuses with blood. X 100. 



2 Photomicrograph of same section as that shown in figure 1. X 280. 



282 



