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 m^^ hand. By this means I cotdd, 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 tiibe into a hair follicle. At first no itching or ir- 

 ritation was felt, except a slight twinge when the bills first 

 penetrated the skin; but little swellings came on a daj^ or 

 two later which itched for over a week. The itching was 

 far more persistent than with mosquito bites. Thej^ 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 b}^ keeping it from clotting." It is more likeh% 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 inultiply but very slowly there is no reason why the^^ 

 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 In' man3^ For this pur- 

 pose, as well as for dipping at anj' 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 



