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tude is when a bird is about to take flight. In this position the body should incline forward, and the wings be slightly raised; this can be accomplished by means of external wires placed beneath them, which are allowed to remain until the bird is dry. The moment of alarm is a striking position. To express this, the one foot must be stretched forward and the other drawn up near the body, and considerably bent. The body must be thrown to one side, with the wing on that side much elevated and spread out, while the other is placed lower and less diffuse; the tail must be expanded, thrown down at the point, and much arched ; the neck should be stretched upward, and the head inclined towards the foot, which is drawn up; the eyelid should also be well rounded. The eagle can be placed in the position of seizing its prey, with wings and tail expanded, head thrown backward and crest erect, gazing upward. The vulture should have drooping wings to portray its sluggish habits. Such descriptions are endless, and indeed needless to a student of nature in its various details.
Remarks upon preparing, relaxing, and mounting dried skins. — The bird should be skinned in the ordinary manner, leaving all the bones of wings in their places, and the skin thoroughly anointed with arsenical soap. The neck should then be stuffed with chopped tow or cotton to its natural dimensions. The upper points of the humeri should be tied together at a distance from each other equal to that of the same when fixed in their sockets, otherwise the distance between the shoulder joints. The skin should next be filled with cotton or tow, and the incision sewed up, the legs turned inwards, crossed, and tied in this position, with a label attached containing descriptions.
One of the most efficacious methods of relaxing dried skins, is that employed by the ingenious Mr. Bullock. A box is made of convenient size, the top of which is free to lift on and off, without hinges or fastenings. The sides, top and bottom within are lined with a coating of plaster of
Paris, two or three inches thick. When any skins are to be relaxed, fill the box with water, and in this condition allow it to stand over night; in the morning any water remaining can be poured off, and the skins placed within. The lid of the box, being grooved, will shut close, and the wooden sides will prevent evaporation from going on.
The box should be set in some damp situation. In twenty-four or forty-eight hours the skins will be sufficiently soft and pliant for mounting. It is necessary before placing the skins within the box, to render the feet and the bill pliable, that these parts should be enclosed in dampened rags or tow. Before moistening, the body should be opened and the inside stuffing taken out with the forceps. Another method is to fill the skin (the former stuffing having been previously removed) with cotton or rags saturated with water, enveloping it with a damp cloth, having wrapped the bill and feet as above stated. The former is preferable, as the latter does not relax all the parts equally. In some cases, however, especially with those of the aquatic families, it is necessary to prepare them after the latter plan, and in this condition to place them in the box described above.
The general method pursued in mounting dried skins is the same as that practiced upon fresh specimens. Difficulty is often experienced in placing the leg wires in position from the dry and shrivelled condition of the tarsi ; this may be overcome by perforating them with the awl used for that purpose (recommended in the former article upon mammalia) previous to inserting the wires. With many of the skins of South American birds, prepared by the natives, a proper adjustment of the wings is found to be impossible. In this case it is necessary to cut them off close to the body, and fix them anew. In replacing the wings the scapulars should be carefully arranged to effectually conceal the joining of the wings. Any feathers disarranged in the operation should be properly adjusted with the small forceps.—To be continued.
AVER. NATURALIST, VOL. III.
THE Fish-hatching establishment at West Barnstable was begun in the spring of 1868. The experiments have as yet been confined mostly to trout, of which we have hatched this year some 60 000, as well as 2000 salmon ova which were procured in New Brunswick by the State Commissioners of Fisheries, by whom they were presented to us. As the process of hatching goes on during the transport of the eggs in wet moss, we lost several by their hatching on the way in the cars.
The place selected for building the ponds to contain the parent trout, was a swampy piece of land at the head of a brook of considerable size, running into the salt water after a course of a mile and a half or two miles, and containing a half dozen or more pure springs, the waters of which formed the fountain head of the stream. Two ponds have thus far been made by excavation, each about forty feet long by twenty feet wide, and from three to four and a half feet deep. They are connected together, the same water being used for both ponds. The supply of water is about eighteen square inches, and is taken from tanks made of plank, varying in size from ten to fifteen feet in length, and from four to ten feet in breadth, sunk in the soft mud at the points where the springs came to the surface, and as deep as was necessary to reach the substratum of sand, which was generally about five feet. These tanks have no bottom planks, and the water wells up through the sand at the bottom, forming reservoirs of living water of even temperature, summer and winter, and not subject to freshet or variation in quantity. The temperature of the springs varies but little from 48° throughout the year.
* EXPLANATION OF Fig. 39. – X, X, X, X, X, X, springs. a, a, a, drains. c, hatching house. D, represents a series of ponds for young fish. E, E, E, spawning ways. b, b, plank troughs. The two ponds between E, E, E, are for spawning fish. The large pond represented by dotted lines, on the right of this, is used as a reservoir for fish. The dotted lines on the cut above the ponds represent a proposed series of ponds. A tank is also placed at this point, indicated by the x on the left of this series of proposed ponds.
There are now about seven hundred parent trout in the two ponds, ranging from three-quarters of a pound to three pounds in weight. It is calculated that the first pond will sustain over 2000 fish of the larger size, while in the second three times that number of smaller fish will thrive. This is allowing one large fish or three of the smaller size to the cubic foot.
They are fed daily with live minnows and shrimp caught on the adjacent salt marshes, or, when they cannot be conveniently obtained, with chopped liver, the roe of codfish, etc.
tc. The ponds are stoned, and one of them which was built in low wet land, is cemented on each side of the stones. Having learned by former experience that trout will spawn in the pond, and the ova thus be lost if its bottom is sandy or gravelly, we covered the bottom, where its nature seemed to invite the fish to this operation, with flat stones, thus obviating the difficulty so far as we have observed. Aquatic plants, mosses, etc., were introduced and now cover the bottom, not only providing a large amount of food in the form of crustacea, snails, etc., but also supplying to the water the necessary chemical elements which are being constantly exhausted by the respiration of the fish.
The water enters each pond through a plank trough, the sides of which are sunk nearly to the level of the ground. These troughs are fifty feet long and three and a half feet wide, and are filled to the depth of six inches with coarse gravel, over which there are six inches of water flowing with a slight current to the ponds. As it is the habit of the trout to, seek shallow running streams to spawn, they eagerly resort to these spawning ways when ready, and are taken by closing the bottom of the way, and driving the fish into a bag net at its entrance into the pond. They are then removed in tubs of water to the hatching house, for the purpose of taking the ova from the female and impregnating them with the milt of the male fish. The modus operandi is as follows: The female fish is grasped with one hand by the back and shoulders, the vent being held under the surface of the water in a tin pan or other vessel partly filled, while with the other hand the abdomen is gently rubbed or pressed toward the vent. If the ova are mature and ready to be shed, a slight pressure is sufficient to extrude them. The same operation is then gone through with the male; if his milt is mature, it will flow in a small quantity into the vessel. A few drops are sufficient to impregnate thousands
The milt and the ova are then gently stirred together, and allowed to remain undisturbed for five or ten minutes. The water is then poured off, new water is gently admitted to wash the eggs, and they are ready to be placed in the hatching troughs.
It may be as well to state here that the spawning time for trout is from October till March, the principal spawning months being November and December. It is generally calculated that a trout weighing one pound will produce 1000 eggs; the larger and smaller ones in the same general proportion. I have known, however, during the past season, a trout of less than half a pound in weight, to deliver 1000 eggs by actual count.