5o 
MAMMALIA. 
weather moderated on the 19th and 20th, and the number of traps 
set was increased to fifteen. These were also visited both morn- 
ing and evening and all were kept in good order, A large propor- 
tion of them were sprung almost every morning, and others were 
plastered up with mud in such a way that they could not spring. 
In fact, on an average, fully twenty traps would be sprung to 
every Mole secured. I think the springpoles used at first were 
too weak, and that a few Moles escaped by forcing themselves 
through the wire loops. But after stiffening the poles we still 
failed to secure more than a small number of Moles in comparison 
with the number of traps sprung. Although the traps remained 
set till the 28th of November, when the ground again became 
frozen and covered with snow, we secured but nine specimens in 
all. Eight were of the Star-nosed variety, while the other was a 
Brewer’s Mole ( Scapanus Breweri ). During the same period 
three more Brewer’s Moles were caught on a side hill near by. 
Dr. Fisher is of opinion that the Moles, in repairing their gal- 
leries, often push a quantity of earth ahead of them in the direction 
of the mounds, and that this springs the trap before the Mole 
has arrived at the loop. In a large number of cases this is a very 
reasonable explanation, of the failure to catch the animal, for the 
traps are frequently found packed full of earth. In other cases 
they dig around the trap, while occasionally a new burrow is ex- 
cavated directly beneath it. Whatever else they may do, they in- 
variably plaster over with mud any exposed part of the trap that 
may appear in the gallery ; and they sometimes bury the whole 
affair by upheaving a hill directly over it. 
The exact method by which the little mounds called “mole hills” 
are produced has long been a matter of earnest inquiry, and I am 
glad to be able to contribute important testimony upon this point. 
Repeated critical examinations of the hills themselves in different 
soils, and occasional observations made at the time of their up- 
heaval, have convinced me that, when in dry earth, it is impossible 
