28 
SHEEP SCAB. 
Lot 5 — Like the preceding, except that they were kept on an 
outer window sill where, according to tests made later, the 
temperature was probably about 7 degrees higher than upon 
the ground, or — 2.8 degrees. 
November 28, all the mites were dead. 
Lot 6 — Ten mites put out January 29. 
February 1, on warming the mites, six, none of which were 
adults, became active; four, all adults, did not revive. Those that 
did revive seemed very sluggish. The minimum temperatures 
for the three nights were 10.7 degrees, 7.8 degrees and 8 degrees 
respectively. 
Lot 7 — A number of mites put out November 23. 
When first examined, January 3, all were dead. Minimum 
temperature during this time, 11.3 degrees. 
Lot 8 — Mites put out November 30. 
Examined January 3, when all were dead. Minimum tem- 
perature for this time, 5 degrees. 
Lot 9 — Mites put out February 6. 
Examined February 9, when all became active on warming. 
They were kept in but a few minutes and then put back. The 
minimum temperature to which these mites was subjected was 
11.8 degrees. 
Examined again March 9, when all were dead. Minimum 
temperature during this time, 5.3 degrees. 
Lots 10 and 11 — Put out February 6 and February 9, re- 
spectively. 
Both lots were examined for the first time March 24, when 
all the mites were found dead. The minimum temperature dur- 
ing the exposure was 5.3 degrees. 
Lot 12 — Put out February 23. 
Taken in and warmed February 24, when all became active. 
The lowest temperature during the night, 5 degrees. 
Lot IS — Mites put out February 6. 
First examined March 9, when all were found to be dead. 
Minimum temperature during this time, — 5.3 degrees. 
The conclusions that may be drawm from the foregoing ex- 
periments are the following: 
First — That the mites can not endure a temperature much 
below zero and survive, even for a single day. 
Second — That the mites can endure a temperature of 5 de- 
grees and live. 
Third — That the immature mites can endure as low, if not a 
lower, temperature than the adults. 
Fourth — That the mites may live very much longer in a 
temperature low enough to keep them dormant than in a warm 
