MISCHIEF OF MEADOW-MOUSE 61 
more of the district, and the main body of mice 
was gradually progressing to fresh fields. 
From this time, however, the abatement of the 
plague was rapid. By March 15, the invasion 
of fresh lands had ceased, though mice contin- 
ued considerably in excess of normal abundance 
until May. By August they had practically 
disappeared from the valley. This scourge left 
a dismal scene of destruction over four-fifths 
of the cultivated area in the district. Of 20,- 
000 acres in alfalfa, 15,000 were so completely 
destroyed as to require replanting. Consider- 
ing the actual losses in crops and the cost of 
restoring the alfalfa fields, and allowing for the 
value of the wheat which replaced alfalfa in 
most of the ruined fields for the season of 1908, 
Mr. Piper estimates the loss in this district at 
$250,000. 
Some interesting particulars are recorded 
as to the diminution of the horde, which was 
preyed upon by a gathered crowd of predatory 
birds, mammals and reptiles, as well as ex- 
tensively poisoned, yet succumbed at last 
mainly to natural mortality,—not to any spe- 
cific bacterial disease. 
