Page:The New International Encyclopædia 1st ed. v. 03.djvu/388

* BOT, BOTPLY. 342 BOTANIC GARDEN. In this way hundreds of eggs may be deposited upon a horse in a short time. The larvse, or maggots, soon form within the eggs, but these do not hatcli unless the horse licks itself, in which case the eggs are carried to the alimentary canal, liatcli almost immediately, and the larva- enter the stomach, where they attach themselves to its wall and remain until fully grown. The inner stomach-wall of a horse is frequently cov- ered with large patches of these larvte densely crowded together. This attachment to the walls of the stomach probably causes an irritation which interferes with the normal action of the glands, or reduces the glandular surface; the grubs also probably extract some nutriment from the walls of the stomach. There can be little doubt that the presence of these grubs is in- jurious to the horse, although some stock-raisers consider this injury insignificant. When fully grown the larvie loose their hold and pass through the pyloric orifice of the stomacli and down through the intestines, occasionally at- taching themselves to the intestinal wall or to the wall of the rectum, causing irritation which is sometimes severe. They are finally voided with the excrement, transformed to pup* near the surface of the ground, and eventually the adult Hies appear. There seems to be but one genera- tion annually. Horses kept in stables are little troubled if they are well groomed. In pastures or on ranges, however, unless the stock is washed every two or tliree weeks, liots are apt to be present. Turpentine, used with care, is consid- ered a remedy for those which succeed in es- tablishing themselves in the stomach. The Ox-BoT, ox-warble, ox-wormal, or heel-fly, as it is termed in the West (sometimes simply 'the grub' ), belongs to a different genus of (Es- tridie and has quite different habits. The Ameri- can species is Hypodernia tiiicnta. Villers, and the European species is Hi/poderma hovis, L. The 'grubs' of this species are found in lumps or pockets in the skin of cattle and it was formerly supposed that the fly laid it.s eggs upon the hairs and that the larvie worked their way through the skin, forming cysts in which they remained through the entire larval life, but it has recently been discovered that the life of the species is more comi)licated. The flies appear early in the spring and attach their eggs to the hairs, particularly of the legs, of cattle, and especially the part just above the hoof, whence comes the name "heel-fly.' The eggs, or the quickly hatching larva', are carried into the mouth of the animal when it licks its legs, and the larva penetrates the walls of the oesophagus by means of its strong spines. After penetrating the oesophagus it casts its skin and becomes nearly smooth, and for several montlis works through the connective tissue between the skin and the flesh, ])enetrating gradually down the neck and ultimately reacliing a i)oint beneath the skin in the region of the l)ack. In the mean- time, all traces of inflammation have disappeared from the oesophagus. When the final position is reached the grub molts again, becomes more spiny, and bores a hole through the skin through which it gets air for breathing. Its presence causes much irritation, and it feeds upon the ]ius and bloody serum which collect. Several in- dividuals usually join together in one of the.'se punctures or sores. When fully grown it forces its way through the skin, drops to the ground, where it transforms to a pupa, and the follow- ing spring the adult fly emerges. The adult looks much like the conunon honey-bee. It is al)out half an inch long, black in color, and is clothed with reddish-brown hairs. An oily ap- plication to the wound will kill the grubs, and some simple antiseptic, like carbolic acid, causes a rapid healing. When the insects are common, however, cattle become emaciated and their skins are spoiled for commercial inirposes by the per- forations. The money lost in the United Stjitcs through the work of this insect is very great. The SilEEi'-BoT (O-'v/cH.s oris. L.) belongs to still another genus of Uistrid;e and differs again radically in habits. The adult flies are smaller than those of the other species mentioned and resemble large house-flies. The color of the head and thorax is dull yellow, but .so spotted with brown as to appear brownish. The abdomen is velvety and variegated with dark brown and straw-color. The female fly lays her eggs in the noses of sheep. They hatch almost immediately, and the larv;e at once commence' to work their way up the nostrils and the nasal passages, caus- ing great irritation, until they reach the frontal sinuses, which are cavities located between the two plates of the skull, and lying one on each side of the central line of the liead and between and a little above the eyes. Here they attach themselves to the membranes which line the sinuses, and feed upon the mucus. The damage caused by this insect has probably been under- estimated. Stiles has found that in Colorado, in some large flocks, at least 25 per cent, of the animals are affected; and after conducting a number of post-mortems he is convinced that in many cases the bots cause the death of the animal. It is the custom in some places to pre- pare 'salt logs' for the sheep to visit. The salt is placed in cavities in the log and the edges of the cavity are smeared with tar, so that the sheep in eating the salt gets a certain amount of tar upon its nose. This is supposed to deter the flies from laying their eggs. A recent remedy proposed by Stiles consists in puncturing the frontal sinuses with a troehar and syringing in a small quantity of gasoline. Other bot-flies affect domestic animals and in tropical regions even man himself. The (E.itrus hominiiti of Linn;i>us and the Drnnatobia iioxialis of (Jcnidot, in Gxiiana. Mexico, and other tropi- cal regions, lay their eggs uj)on the skin of monkeys and of human beings, and the larvse form cysts under the skin, nnich like those of the ox-bot. The enuisculating bot-fly {Cutcre- hra enuisciilafor. Fitch) lives in the larval state in the inguinal and axillary regions (testicles) of squirrels and gophers. The rabbit bot-fly (Cutrrehra cuniciili. Clark) in the larval stage forms a large tinnor in the skin of the common rabbit. Other species affect ndndeer in Europe, and deer, elk, and antelopes in America. The history of many American species, with il- lustrations, may be found in Osborn's Insects Affecting Dome.itic Animals (Bulletin No. 6, n.s., Div. of Entomology, U. S. Dept. Agri., Washington, IHlMi). which also contains an ex- tensive bibliography of the (Estridie. BOTANIC GARDEN (Ok. /SotohkAs, botan- ih'os, iiertaining to IhtIis. plants; see BoTANV). . area upon which is grown a collection of plants primarily for scientific purpose-s. In such a collection the idea may be to include as