For the display of naked nests, Captain Bendire uses a very simple but ingenious little standard made of four wires twisted together so as to form an upright stem, a horizontal platform of the right size, with four perpendicular standards to receive and hold the nest. These standards are easily bent to conform to the shape of the nest, and if the upper ends project above the nest they are snipped off with a pair of cutting pliers. The illustration on page 93 (Fig. 22) shows the exact character of the wire standard, and Fig. 23 shows it in use, supporting a naked nest. Captain Bendire's method of labelling his nests is also shown in full. It is to be noted that the locality of the specimen exhibited, and the name of the collector, appears in full upon the label—two features which should never be omitted on a specimen that is of sufficient value to occupy a place in a museum. Nevertheless, by less careful curators both these statements are frequently omitted from labels.
[a]Fig. 23.]—Nest on Wire Standard, with Labels.
Collecting Eggs.—In connection with a collection of nests, each nest holding its own lawful and original contents, a good collection of birds' eggs possesses much interest and beauty.
In collecting and preserving eggs, the most difficult feature of all is to remove the embryos successfully. In the days when I diligently collected eggs in many lands, it seemed to me that out of every dozen eggs I gathered, about thirteen contained from one to two embryos each! But there are ways in which this difficulty can be successfully overcome.
The full set of eggs laid by a bird for one brood is called a "clutch," and in collecting it is of scientific importance that whole sets should be collected and always kept separate, and the number of eggs in each set taken should be recorded.
Eggs are always blown through a small, round hole in the middle of one side, preferably in each instance on the poorest side of the egg, if it has one. Of course, the smaller the egg, the smaller the drill must be, and the greater the care in handling. It is often a good plan to pierce the shell with a needle in order to furnish the drill a point of attack. If an egg is cracked, or happens to be of such value that it must be saved at all hazards, reinforce it by pasting narrow strips of goldbeater's skin or court-plaster across the line of fracture.
Having drilled the hole, insert the end of a small wire, having a small portion of the end bent at a right angle, and if the embryo has not begun to develop, or happens to be quite small and soft, twirl the wire rapidly between your thumb and finger, to thoroughly break up the contents of the egg. Having accomplished this, insert the tip of your blow-pipe (the best in the world consists of a tube of glass bent at a right angle and terminating in a fine point, with the large end set in the end of a rubber bulb, which saves the mouth and lungs all trouble) and with gentle and gradual pressure blow in air. Hold the egg with the hole downward, of course, so that the contents will run out freely. Go slowly and carefully, even coaxingly, for too great pressure will burst any ordinary egg in two parts very neatly. If the embryo is small and disposed to be accommodating, help it out by inserting the point of your smallest scissors, snipping it to pieces, and then drawing out the parts, one by one, with your smallest forceps.
Having emptied the egg of its contents, introduce some clear water by way of the blow-pipe, wash out the inside thoroughly, and in case the egg is in a clean, healthy condition, it can now be laid away on cotton or cornmeal, with the hole downward, to drain and get dry. Observe this point, however. The thin, membranous lining of an egg, which the point of the drill pierces but cannot cut away, often closes together inside the hole so closely as to retain, for some time, whatever water might chance to remain. For this reason it was my custom to cut away this membrane around the edges of the hole. Captain Bendire remarks that "eggs that have been thoroughly cleaned will retain their original color much better, and insects or mice are not so apt to trouble them."
Removing Large Embryos.—It often happens that eggs are taken quite near the hatching point, containing embryos so lusty in size, and so "very fillin'" that their successful ejectment seems impossible. Nil desperandum. The way out of the difficulty is through a very small hole. On this point I appealed to the highest authority, Captain Bendire, and he kindly gave me, in general substance, the following directions: