A treasury of natural history; or, a popular dictionary of animated nature ... To which are added, a syllabus of practical taxidermy, etc / [Samuel Maunder].

Samuel Maunder

Date:: 1848

Credit: A treasury of natural history; or, a popular dictionary of animated nature ... To which are added, a syllabus of practical taxidermy, etc / [Samuel Maunder]. Source: Wellcome Collection.

105/854 page 83

$' during summer and autumn. The spawn is shed in the beginning of winter in deep water; and it retreats altogether from our shores in severely cold weather. The young of tliis fish are commonly known by the name of Chads. The Sea bream is not very highly esteemed for the table, cither txesh or salted. i BREEZE-FLY. {CEstrus; (Estridee.') The insects we are about to describe are produced : from larvae which when existing in horses are termed bots; in sheep, maggots; and in cows and oxen, womils; and these three represent three di\’isions of the family, dif- fering essentially in their history. The per- fect insect produced from each kind of larva is properly termed a Breeze-fly. Before we proceed fWther, however, we beg to state that the observations wliich follow arc taken from Mr. Newman’s History of Insects, who quotes as his authority “ An Essay on the Bots of Horses and other animals, by Bracy Clark, F. L. S.” “ The opinions of the Brcczc-fly of the horse, or bot^ ns it is usually termed, as to the benefit or injury derived from it, are very opi)osite ; some obser\’ers go so far as to as- sert that the larvaj occasioitally completely I>erfbrate the stomach of the horse, causing disease, pain, and even death ; others regard them as perfectly innocuous ; and one author [Mr. Bracy Clark], whose careful and labo- rious investigations entitle his opinions to the greatest respect, believes the effect of bots to be salutiferous rather than otherwise; aud from liis masterly essay the following particulars are extracted. “ The female fly, in approacliing the horse for the purpose of oviposition, carries her bo<ly nearly upright in the air, the protruded ovipositor being cur\'cd inwards and up- wards. Suspending herself for a few seconds before the part of tlic horse on which she intends to deposit the egg, she suddenly darts upon it, and leaves the egg adiiering to the hair: she hardly appears to settle, but merely touches the hair with the egg held out on the extreme point of the ovi- positor, the egg adhering by means of a ghi- tinous liquor with wliich it is covered. She tlien leaves the hor»e at a small distance, prepares a second egg, and, poising her- self before the j)art, deposits it in the same way : the liquor dries, and the e^g becomes firmly glued to the hair. This is repeated till four or five hundred eggs are sometimes placed on one horse. The skin of the horse is usually thrown into a tremulous motion on the touch of the insect, which merely arises from the very great irritability of the skin and cutaneous muscles at this season of the year, occasioned by the heat and con- , tinual teasing of the flics, till at length these muscles api>car to act involuntarily on tho I slightest tfjuch of any body whatever. “ The flv does not dciKwit her eggs at ran- dom on the horse’s Inxly, but selects those parts which arc most likely to be nibbled by the horse : the inside of the knee is fre- quently cho4cn, but all naturalists must have remarked how commonly the eggs of the bot are <leiK)sitcd on that j)artof a horse’s shoulder which he can never reach with his mouth, and thus, to a casual observer, it w’ould seem that they must ijerish, and fail iu the object for which their parent designed them. Now there is a provision of nature which exactly counteracts this difficulty. When horses are together in a pasture, and one of them feels an irritation on any part of the neck or shoulder which he cannot reach with his mouth, he ^vill nibble another horse in the corresponding part of his neck or shoulder, and the horse so nibbled will immediately perform the kind office re- quired, and begin nibbling away in the part indicated. The horses, when they become* used to this fly, and find it does them no injury by sucking their blood, hardly regard it, and do not appear at all aware of its object. “ When the eggs have remained on the hairs four or five days, they become mature, after wliich time the slightest application of warmth and moisture is sufficient to bring forth in an instant the latent larva. At tliis time, if the lips or tongue of the horse touch tlie egg, its operculum is throvni open, and the young larva liberated: this readily adheres to the moist surface of the tongue, and is from thence conveyed with the food to the stomach. It is worthy of remark, that it is probable the greater part of tlie eggs deposited by this fly are taken up in consequence of the irritation of other flies, as the Tabani and Stomoxidesy wliich, by perpetually settling on the skin, occasion a horse to nibble himself on those parts, aud thus receive the larvae on the tongue and lips, whence they are introduced into the stomach. * * * The larva, when matured, quits the stomach of the animal and falls to the ground, and finding a convenient place of retreat, undergoes its change to a chrysalis, the skin then losing its organization, and changing in colour from a wliitish red to a reddish broivn. After remaining torpid in the chrysalis state a few weeks, the super- fluous moisture being removed and the parts of the future insect hardened by drying, it bursts from its confinement, and the fly makes its exit at the small end of the case. A few hours after quitting their shell they become dry, take wing, and seek their mates. “A second species of Breeze-fly has a still more wonderful history : its eggs arc laid in the nostrils of sheep, from one to seven or c ght in each individual, and these on be- coming larvae,enter the frontal and maxillary sinuses, and even the horns, and feed on their secretions : when the larVoj arc young they arc perfectly white and transparent, except two small black horny ]>lates : as tliey increase in size the upper surface be- comes marked with two transverse brown lines on cacli segment, the anterior being shorter and narrower than the posterior ; and some 8i>ots arc also observable on tho sides. The body consists of twelve segments besides the head. These larvo3 move witli [ considerable activity, holding with their | tentacula to a fixeef point un<l drawing up the body. When full grown the larvie fall I through the nostri Is of tlie sheep, and change | to the pupa state lying on the earth or ad- hering to the side of a blade of grass: in$