SHEEP SCAB. 
23 
WHALE-OIL SOAP. 
Used in the proportions of one pound to two gallons of water, and 
in one-half and one-fourth of this strength, and with no apparent effect 
in any case. In the strongest preparation many mites were alive at the 
end of sixty-four hours. 
EXPERIMENTS WITH THE EGGS. 
There is a prevailing opinion that the eggs are not killed 
by the applications that destroy the mites, and that, as a conse- 
quence, a second dipping is made necessary to destroy the young 
mites hatching from the eggs that survived the first treatment. 
It is commonly recommended to dip a second time from ten to 
fourteen days after the first treatment, but I can not find that 
anyone has actually determined the time required for the eggs 
to hatch. There is also the greatest difference of opinion as to 
the length of time the eggs may survive when off the sheep, 
some thinking they may live for years, and others that they can 
not survive more than a few weeks. These are all matters of 
very great importance, and the experiments tabulated below 
were conducted for the purpose of throwing light upon them. 
The eggs are difficult to obtain in sufficient numbers for experi- 
mental purposes, and it is not a very easy matter to keep them 
under a very close ai)])roach to natural conditions. The method 
that I adopted was to use small glass tubes supplied with corks. 
The cork, in each case, was removed, moistened with saliva on 
the inner end, the eggs for the particular experiment placed upon 
it, where they adhered without trouble after the cork was re- 
placed. The tubes were then carried in an inside vest pocket 
during the day and kept in a warm place during the night. Any 
ordinary low temperature seemed to have no effect upon the eggs 
except to lengthen the period of incubation. 
Tabulated Experiments with Eggs of Sheep Scab-Mite. 
Date of 
Applica- 
tion 
Date of 
Notes 
Number of Eggs 
Treated With 
Strength of Dip 
Hatched 
Unhatched 
Nov. 
27 
Dec 
II 
0 
9 
Black Leaf. 
. I to 40 
Nov. 
7 
Nov. 
12 
10 
0 
Black Leaf ... 
I to 42 
Nov. 
19 
Nov. 
27 
I 
0 
Black Leaf. .. . 
...I to so 
Nov. 
17 
Nov. 
26 
2 
7 
Phenyl Hydrazine 
Full strength 
Nov. 
17 
Dec. 
9 
0 
7 
Crude Aniline. 
Full strength 
Nov. 
17 
Dec. 
9 
0 
2 
Crude Aniline 
One-half strength 
Nov. 
7 
Dec. 
9 
0 
2 
Zenoleum Dip. . 
I to 100 
Nov. 
27 
Dec. 
II 
0 
5 
Zenoleum Dip 
I to 200 
Dec. 
13 
Dec. 
24 
0 
Zenoleum Dip 
I to 200 
Feb. 
7 
Feb. 
24 
0 
4 
Zenoleum Dip 
I to 200 
Feb. 
7 
Feb. 
27 
0 
12 
Zenoleum Dip 
I to 200 
Nov. 
13 
Nov. 
26 
0 
6 
Zenoleum Dip 
I to 400 
