DISEASES OF THE SKIN AND SUB-TISSUES. 283 



breathing-holes in the body corresponding with those in the body 

 of the caterpillar from which it was produced — the same body, in 

 fact, remaining after the wings are developed. If you dip a feather 

 in oil, and smear the two spirules nearest the tail, the lower por- 

 tion of the body will be paralyzed so far as these holes. Proceed- 

 ing upward, you may paralyze the whole body until you come to 

 the last two, which are situated just below the jaws. So long as 

 these remain open, the insect will continue to breathe, but if these 

 are now closed, he dies immediately. To exterminate lice upon 

 any animal, it is only necessary to cover the animal completely 

 with grease or oil. The simplest and cheapest oil is best — lard, 

 fish oil, or any other that is at hand. When the lice have not 

 become so numerous as to produce the disease known as pityriasis, 

 or rcunge, this application, undoubtedly, is the best that can be 

 used. In addition to being effective, it is perfectly harmless. 

 Stock breeders should always recollect that prevention shows wis- 

 dom, « nd saves annoyance and expense ; and, by neatness, cleanli- 

 ness and comfort, the health of the animal will be insured, and the 

 animals will not become infested with the troublesome parasites. 

 Poultry lice affecting horses. — Horses, when located near a hen- 

 roost, are apt to be infested with poultry lice. The remedy is the 

 same as in the case of the common louse. 



Diseases of the Heels (Grease, Scratches, " Wateb 

 Farcy," "Weed Shot," "Milk Leg"). 



In olden times grease, or scratches, and cracked heels, were not 

 only very prevalent but very formidable affections. Before 

 veterinary surgeons were employed in the British Army, many 

 thousands of valuable horses were condemned as useless for active 

 service in consequence of the prevalence of that loathsome affec- 

 tion known as inveterate grease ; but now, in consequence of the 

 presence of veterinary surgeons, and the consequent improved 

 system of management in camp and stable, grease is almost un- 

 known. Most veterinary writers contend that grease almost 

 always arises from improper management of the horse, yet I have 

 seen it occur in horses that were well cared for and properly 

 treated. The truth is, some horses are predisposed to affections 

 of the skin of the heels and the sebaceous glands of the same ; 

 and, altnough cleanliness and good management may stave off an 

 attack for a long while, yet when the system abounds in morbifio 



