130 AGRICULTURAL REPORT. 



Cattle arc frequeutly annoyed and injured by a skiu-bot fly, {Hypo- 

 derma {(Estrus) bovis,) (Fig-. 18,) tbc larva? of wbicb reside in large open 

 tumors or abscesses under tbe skin, on tbe backs of oxen, cows, &c. 

 These in England arc known by tbe local name of wormals, (i^robably 

 derived from tbe words "worm-boles,") and tbe larvje subsist on tbe pur- 

 ulent matter produced by tbe constant irritation caused by tbe grub. 

 Tbe larvis remain all Avinter iu tbese tumors, and wben fully developed 

 tbe following season tbey squeeze tbemselves tbrougb tbe aperture in 

 tbe skin, purposely kept open by tbe larva, fall to the ground, cbange 

 to pupiB in tbe shrunken, oval, and hardened brown skin of tbe larva, 

 and appear, from tbe mouth of Jane to September, as perfect flies, which 

 again lay their eggs iu or on the backs of cattle. A very simple and 

 safe remedy for the skin-bots is to enlarge tbe opening of tbe tumor with 

 a knife and press tbe sides of the swelling until the larva is squeezed 

 out, taking care, however, not to burst the skin of tbe grub. Tbe 

 wound then heals without any further remedy, if it is only kept clean. 



The stomach-bot fly of tbe horse ( Gasteropliilus ( Gastrus) cqid^) (Fab.) 

 is very troublesome to horses when kept in open pastures. The larvae 

 live in the stomach and are commonly known as " bots." The eggs are 

 deposited by tbe female on the hair of the horse, commonly on the knees 

 and shoulders, and after being bitten or licked oif by the animal, batch 

 almost immediately when in the mouth, hy tbe heat and moisture, and 

 are swallowed with the food. When once iu the stomach the young bots 

 or grubs fasten themselves, by means of hooks at the anterior portion of 

 tbe body, to tbe coating of the stomach, frequently forming clusters. 

 When fully grown these bots let go their hold upon the stomach, and 

 are voided witli the excrements and fall to the earth, iu which they bury 

 themselves. Tbe skin of tbe larva then shrinking and hardening, an 

 oval brown case is formed, in which is formed the pupse, and after forty 

 or fifty days they emerge through a hole burst through the puparium or 

 cocoon-like case, iu the form of bee-like two- winged flies, which again 

 deposit their eggs on horses. Professor Verrill, in his interesting and 

 able report, says " the bot- worms have been accused of perforating the 

 walls of the stomach, and this may possibly be the case in very rare 

 instances, but the perforations of tbe stomach so often found in post- 

 mortem examinations are generally caused by the digestive action of 

 the gastric juice after the death of the animal." Dr. Harris states that 

 " no sure and safe remedy has yet been found for removing bots from 

 tbe stomach." Roller recommends animal oils, but Mr. Bracy Clark 

 doubts the beneficial results, as oils which might seem efficacious, by 

 closing tbe spiracles or breathing-pores of the bot, and thus destroy it, 

 are soon reduced to soap and digested so as to be scarcely of any avail ; 

 and, as prevention is better than cure, he suggests an efiectual mode of 

 preventing the introduction of the bots into the stomach, by washing 

 off the eggs (which on dark horses are \ery conspicuous, from their 

 lighter color,) as soon as observed, from the knees, mane, and shoulders 

 of the horse, or by removing them with a pair of scissors. It is believed 

 by many farmers that molasses and milk taken by the horse will cause 

 the bot to let loose its hold on the coating of the stomach to feed upon 

 the sweet mixture, and a powerful purgative being given soon afterward 

 the horse will eject the bot before it has had time to refasten itself to the 

 stomach. Bleeding the horse in the mouth or nose, and causing him to 

 swallow^ the blood, is said by some to have the same effect. Entrails of 

 chickens and pieces of raw flesh have also been used, but we have no 

 faith iu such remedies, and they are merely mentioned as having been 

 used. Some farmers recommend the use of salt or brine in the horse's- 



