DISEASES OF THE DIGESTIVE ORGANS. 171 



the heart for its place of abode ; another inhabits the arteries ; a 

 third, the kidney, ^fyriads of minute worms lie coiled up in the 

 voluntary muscles or in the areolar tissue that connects the flesb 

 fibers. The guinea-worm and chigoe bore through the skin, and 

 reside in the subajacent reticular membrane. Hydatids infest 

 vario'is parts of the body, but especially the liver and l)rain. A 

 little flidvc, in general appearance mudi like a minature Hounder, 

 lives, steeped in gall, in tlie biliary vessels. If you squeeze from 

 the skin of your nose, what is vulgarly called a maggot (the contcMita 

 of one of the hair-pellicles), it is ten to one that you find in tiiat 

 small sebaceous cvlinder several animalcules, exlremelv minute, 

 yet exhibiting, under the microscope, a curious and complicated 

 structure. Even the eve has its living inmates: but it is in the 

 alimentary tube that we are most infested with these vermin." 



It is evident, from competent testimony, that these, as well as 

 other kinds of parasites, are always more or less injurious; hence 

 the same may be true as regards the bot in a horse's stomach. The 

 best authority we have for the origin and history of the bot is 

 Braoy Clark, V. S., a selection from whose works is here in- 

 trod u^od : 



'^Tlie (Estrus Egui, or the Stomach Bot. — "\Micn the female ]iaa 

 been impregnated, and the eggs sufficiently matured, she seeks 

 among the horses a subject for her purpose; and approaching him 

 on the wing, she carries her body nearly upright in the aii, and 

 her tail, which is elevated or lengthened for the purpose, curved 

 inward and u])ward. In this way she approaches the part where 

 slie designs to deposit the egg, and, suspending herself for a few 

 second? before it, suddenly darts upon it, and leaves the egg ad- 

 hering to the hair. She hardly appears to settle, but merely 

 touches tiie hair, with the ogg held out on the projected ])oint of 

 the abdomen. The egg is made to adhere by means of a ghiti- 

 rious liquor secreted with it. She then leaves the horse at a small 

 distance, and prepares a second egg, and, poising herself before the 

 part, deposits it in the same Avay. The liquor dries, and the egg 

 becomes firmly glued to the hair. This is repeated by th.ese flit^ 

 till four or five hundred eggs are sometimes placed on one horse. 



The skin of the horse is usually thrown into a tremulous motion 

 OD the touch of this insect, which merely arises from the very great 

 irritability of the skin and cutaneous muscle? at this season of the 

 rear, occasioned bv the heat and continual teasing ct the flies, till, 



