_Diseases caused by Bot Flies._—The maggots bore into the walls of the stomach and intestines until they reach the layer in which the blood-vessels, lacteals, and lymphatics ramify; they then suck the juices found in these vessels, and also serous fluids. In small numbers they are often almost harmless, but when a great many are present they hinder the secretion of the digestive juices. They may also set up inflammation of the intestinal coats, or may cause death by internal bleeding if they perforate the wall of an artery. In foals they often bore right through the wall of the intestine, and enter the abdominal cavity, where they may set up inflammation of the peritoneum or of the mesentery. There may be as many as a hundred or two hundred maggots in the stomach or intestine, and they then cause, at the very least, digestive disturbances and colic. If the maggots (_G. nasalis_) get into the windpipe (or larynx) they interfere with the breathing; if into the gullet, with swallowing. In either case death may ensue (winter, early spring). _Remedies_: Killing the flies as they lay their eggs. Removing the eggs by brushing, combing, and washing; the last is best done with warm water, to which some caustic potash is added. Rubbing the lips and nostrils, neck, chest, and fore legs with walnut leaves, or a decoction of the same. ────────────────────┬──────────────────┬──────────────────┬────────────────── SPECIES. │ FLY. │ EGG. │ MAGGOT. ────────────────────┼──────────────────┼──────────────────┼────────────────── =Horse Bot= │½ to ⅖ inch, very │White: on the │At first flesh (_Gastrus equi_). │ hairy, like a │ hairs of the │ red, then │ humblebee; │ mane, neck, │ yellowish-brown. │ brownish yellow.│ chest, fore │ Lives in the │ Fore part of │ legs, and hind │ stomach of the │ thorax with │ feet of horse. │ horse, often in │ yellowish-brown,│ │ large numbers. │ hind half with │ │ │ black hairs. │ │ │ Abdomen with │ │ │ brown hair in │ │ │ front, │ │ │ brownish-yellow │ │ │ behind. │ │ =Cattle Bot= │Male about ½ inch,│Black: on the same│First yellowish (_Gastrus_ │ brown, closely │ parts of the │ grey, then _pecorum_.) │ covered with a │ horse’s body as │ blood-red. First │ mixture of │ in the preceding│ in the small │ yellowish and │ species; │ intestine, and, │ black hairs. │ exceptionally on│ for some time