142 THE SHEEP-TICK. 
difficult to explain the very large numbers of ticks sometimes 
found upon a single sheep. 
Dr. Curtice who studied the parasites of the sheep most 
thoroughly, writes: ‘‘to feed them they were placed upon 
the back of my hand. By this means I could, with a lens, 
watch them bore into the skin and see the abdomen slowly 
enlarge as they drew in the blood. They had some difficulty 
in penetrating the thick skin, but usually succeeded by slip- 
ping their tube into a hair follicle. At first no jtching or ir- 
ritation was felt, except a slight twinge when the bills first 
penetrated the skin; but little swellings came on a day or 
two later which itched for over a week. The itching was 
far more persistent than with mosquito bites. They must 
in this way cause lambs much discomfort. It was at first 
thought that a fluid could be seen running from the parasite 
to the hand through the bill, but no more was thought of it 
until the elevations began to rise and itch; then it appeared 
that the little pests had secreted a poisonous fluid. The 
office of this secreted fluid is probably to assist the flow of 
blood by keeping it from clotting.”’ It is more likely, how- 
ever, that such poison is injected to draw the blood to the 
spot inflamed by it. 
REMEDIES.—The presence of such parasites must cause con- 
siderable itching, and particularly so to lambs with a tender 
skin, and if very numerous they can cause serious trouble. As 
they multiply but very slowly there is no reason why they 
should ever become so numerous as is really the case, even in 
so-called well-kept herds. If not numerous, tobacco or other 
mixtures used for sheep-dips will rid the animals of these in- 
truders. Such remedies should be used at shearing time, 
when all parasites not removed with the wool can be readily 
reached. Fall dipping is advised by many. For this pur- 
pose, as well as for dipping at any other time, a kerosene- 
emulsion is recommended. This is made in the following 
manner: ‘“‘Churn fresh skimmed milk and kerosene to- 
gether in the proportion of one gallon of milk to two gal- 
lons of kerosene, either in a churn or by using a force-pump, 
until an emulsion is made. The method of using a force- 
pump is to set it in a vessel containing the mixture and to 
