The Zoologist/4th series, vol 4 (1900)/Issue 710/Editorial Gleanings
Formaldehyde as an aid in collecting ornithological specimens is the subject of a communication by Mr. Joseph Mailliard to the last number of the 'Auk' for July. It appears that formalin can be procured at a much lower rate under the trade name of "formaldehyde." By its aid the collector is placed in an independent position in regard to the number of specimens he may collect in a day, as with its aid he can keep a number in good condition until time admits of preparing them for his collection. With an old-fashioned veterinary hypodermic syringe, and a bottle of saturated solution of formaldehyde, Mr. Mailliard is now provided on all his expeditions. This syringe holds one teaspoonful, and this is sufficient for a bird as large as a Partridge. The sharp needle is punched into the abdomen in one or more places, a few drops are sent down the throat of a bird to be saved, and, if to be kept for some days, a little is injected into the brain by opening the bill and forcing the needle upwards and backwards between the eyeballs. In place of a regular hypodermic, a common glass syringe, or even an eye-dropper, can be made to answer, especially if the end is heated and drawn out to a sharp point, as in an egg-blower. The amount injected and the strength of the solution must depend upon the size of the bird. Formaldehyde comes in saturated solution of nominally 40 per cent., while from 4 per cent, to 10 per cent, is what may ordinarily be used. For birds up to the size of a Partridge, 4 per cent, is sufficiently strong; from this to the size of a Duck, 8 or 10 per cent.; and for Geese and very large birds a comparatively smaller amount of the full strength seems more satisfactory than a larger amount of a weaker solution. It is well to avoid, as far as possible, having one's hands come in contact with the strong solution, as this is apt to harden the skin of the fingers, and cause cracks, into which arsenic may be introduced. Upon the basis of the original solution being 40 per cent., it is a simple matter to approximate any desired strength by mixing in a separate bottle one part of the solution to so many parts of water roughly estimated. The strength and amount necessary for different birds will soon be learned with a little practice. If too much or too great a strength is used upon small birds, the body becomes more or less hardened and dry, making it exceedingly difficult to skin the specimen. Care must also be taken to avoid using more than is absolutely necessary in the throat, as the thinness of the gullet allows the formaldehyde to act directly upon the skin of the neck, which is apt to become so stiff and dry as to cause it to tear in the effort to skin the bird over the head. A few drops only will suffice for the preservation of this part of the bird, except in the case of a large crop full of decomposing food. When properly treated with this solution, and properly cooled off in the first instance, birds will keep a week even in warm weather in sufficiently good condition to make a fair skin.
Dr. Alphæus S. Packard, the well-known American entomologist, who is now in London, has ready for the press a volume entitled "Lamarck, the Founder of Evolution; his Life and Work. With Translations of his Writings on Organic Evolution." Dr. Packard has sought and obtained much original material for his publication in France, and the work will probably be published in England.
In connection with the above, it is interesting to know that Darwin's great work, 'The Origin of Species,' will be out of copyright in about a couple of years, and that the publisher has decided to issue during the coming autumn an edition in large type, well bound and well printed, at a price which will bring it within the reach of all—half-a-crown.
The monthly magazines still show by their contents that the ordinary reader is interested in the many curious details of animal life. In the June number of 'Pearson's Magazine,' René Bache writes on fish-culture in trains in the U.S.A., and describes the special railway-car used for the transportation of fry and eggs, under the direction of the national "Fish Commission."
Supposing the car is drawn up at one of the Fish Commission's central stations, and the captain of the car is to receive for transportation a cargo of 2,600,000 young Shad, and 400,000 Shad eggs; as quickly as possible the newly-hatched Government Shad will be taken aboard in about one hundred cans resembling milk-cans, each containing 20,000 fish. The eggs, in similar shipping-cans, will be rapidly loaded; the car will be attached to a train, and the journey will commence. The captain of the car and his four trained assistants must account for every one of the 3,000,000 lives entrusted to their care. This is no light responsibility, for young fishes die on slight provocation, and it is not surprising that the captain in charge of them all should be fairly overwhelmed with urgent duties. He has already sent telegrams to the traffic manager of every line over which he is to pass, making arrangements for the hauling of the car, so that there shall not be a moment's unnecessary delay. He has telegraphed in advance to various points on the route for supplies of ice and water, and he has also prepared type-written instructions for each of his subordinates, telling them their precise duties throughout the journey.
As soon as they have been taken on board the young fish are at once examined, and the water in their cans is aerated. This is accomplished by drawing off a certain portion of the water into a suitable receptacle, dipping it up with a dipper, and letting it fall again, so as to mix air with it. Fresh water is added, and ice is put in to chill it to the proper temperature of 60°, when it is returned to the can. This process occupies more than an hour, and must be repeated every two hours. If any of the young fishes are dead they sink to the bottom, and are taken out with a syphon tube.
Meanwhile the 400,000 Shad eggs are transferred from the shipping-cans to the batteries of hatching-jars. The jars are put on shallow trays, which are placed over refrigerating tanks. There are forty-eight jars, each capable of hatching 100,000 eggs at one time. When the hatching apparatus has been set in operation it requires hardly any further attention, a continuous stream of water passing through the jars, and keeping the ova agitated. When hatched the young fish, being lighter than the water, pass out of the receptacles, through syphons, into glass aquaria, from which they may be taken with gauze nets when required.
When the car reaches one of the places on its journey where a consignment of Shad is wanted, an attendant takes perhaps fifteen cans, containing 300,000 fish, drives to the water that is to be stocked, and in the cool of the evening lowers the cans gently into the water, and releases his captives to their first experience of the world. The chances are that one in ten will live to grow up; the remainder will be eaten.
Anything that relates to Gilbert White is of interest to naturalists, and when we have an article by Prof. Newton on "Gilbert White and his Recent Editors" ('Macmillan's Magazine,' July) we know that we shall have sound views, with pungent criticism. And we are not disappointed. The last two editions are certainly not bepraised, and the opinion as to former editions will probably receive general acceptance, though editors have a rough time. As Prof. Newton severely observes:—"The work itself has never suffered from its misusage by editors, of whom it has had so many, a few good, some indifferent, and several bad. If anything be needed to prove White's right to be considered a naturalist of the first order, it may be found in the fact that his most ignorant editor has been unable to degrade him from that rank, and how ignorant some have been would take too long to tell." Some, however, are "regarded as experts, and their work therefore to have real value. Among them are such men as Blyth, Jardine, Rennie, and Bennett, the labours of the last two forming the foundation of the excellent edition (or editions, it must be said) of Mr. Harting; and the late Prof. Bell, who lived for forty years in what had been White's house at Selborne, and, possessing advantages far greater than any of his predecessors or successors, was able to give so much additional information that his edition still remains, and is likely for many years to remain, the standard. His biographical memoir, too, contains more numerous details of the author than had been before accessible; but for a complete Life we must await that which his great-great-nephew, Mr. Holt-White, is understood to have in the press."
Mr. Frank T. Bullen has written in the 'Strand Magazine' for July on the subject of "Sociable Fish." On the question of the sociability of the Pilot-fish with the Shark, the author writes as follows:—
"Does the Pilot-fish love the Shark? Does it even know that the Shark is a Shark, a slow, short-sighted, undiscriminating creature whose chief characteristic is that of never-satisfied hunger? In short, does the Pilot-fish attach itself to the Shark as a pilot, with a definite object in view, or is the attachment merely the result of accident? Let us see.
"Here is a big Shark-hook, upon which we stick a mass of fat pork two or three pounds in weight. Fastening a stout rope to it we drop it over the stern with a splash. The eddies have no sooner smoothed away than we see the brilliant little blue and gold Pilot-fish coming towards our bait at such speed that we can hardly detect the lateral vibrations of his tail. Round and round the bait he goes, evidently in a high state of excitement, and next moment he has darted off again as rapidly as he came. He reaches the Shark, touches him with his head on the nose, and comes whizzing back again to the bait, followed sedately by the dull-coloured monster. As if impatient of his huge companion's slowness, he keeps oscillating between him and the bait until the Shark has reached it, and without hesitation has turned upon his back to seize it, if such a verb can be used to denote the deliberate way in which that gaping crescent of a mouth enfolds the lump of pork. Nothing, you think, can increase the excitement of the little attendant now. He seems ubiquitous, flashing all round the Shark's jaws as if there were twenty of him at least. But when half a dozen men, "tailing on" to the rope, drag the Shark slowly upward out of the sea, the faithful little Pilot seems to go frantic with—what shall we call it?—dread of losing his protector, affection, anger, who can tell? The fact remains that during the whole time occupied in hauling the huge writhing carcase of the Shark up out of the water the Pilot-fish never ceases its distracted upward leaping against the body of his departing companion. And after the Shark has been hauled clear of the water the bereaved Pilot darts disconsolately to and fro about the rudder as if in bewilderment at its great loss."