268 UPLAND AND MEADOW. 



liberate change of haunt from the uplands to the mead- 

 ows, brought about by the excessive dryness of the 

 earth ; for often there is no appreciable moisture even 

 at a depth thrice that of their deepest burrow. At 

 such a time, these creatures have one other means of 

 escaping the discomfort of a drought — they can sesti- 

 vate, or become torpid during the excessive heat; just 

 as they would hibernate under certain conditions, dur- 

 ing winter. Such an occurrence is probably very rare 

 in this latitude, as compared with hibernation ; but 

 that many a poor mouse has been picked up, or trodden 

 under foot, in midsummer, which was supposed to be 

 dead, but w^as simply in an sestivating condition, is un- 

 questionably true. 



While rambling about, I have found certain limited 

 spots which were overcrowded with field mice ; but 

 find no reference in tlje books to the migrations of 

 these mammals, if, indeed, they come in one body to 

 such places. Something strongly suggestive of collec- 

 tive migration I have but once witnessed. It was late 

 in the month of June. No rain had fallen for tliree 

 weeks, and the upland fields were dusty, the surface 

 soil was hot to the touch, and the grass was as brown as 

 well-cured hay. Passing along the brow of the bluff, 

 shortly before sunrise, my attention was called to a 

 black mass moving in a wavy line towards the meadow. 

 I at once thought of a large snake, and hastened to 

 overtake it, but it proved to be a column containing 

 perhaps a hundred of wild house mice, each one run- 

 ning slowly in an irregular way, sometimes singl}', 

 sometimes two abreast. At my near approach they 



