The Zoologist/4th series, vol 6 (1902)/Issue 729/Editorial Gleanings

by editor W.L. Distant

 

EDITORIAL GLEANINGS.

 

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At the meeting of the Zoological Society, on the 4th inst., Dr. H. Lyster Jameson, M.A., read a paper "On the Origin of Pearls." The author's observations referred especially to Mytilus edulis, the Common Mussel. The pearls were found to be due to the presence of parasitic Distomid larvæ, which entered the subcutaneous tissues of the Mussel, and became surrounded with an epidermal sack similar in its characters to the outer shell-secreting epithelium of the mantle. If the Distoma died in the sack it became calcified, and formed the nucleus of a pearl, the pearl arising, like the shell itself, from the calcification of the cuticle of the epithelial cells. The parasite sometimes migrated out of the sack, in which case the nucleus of the pearl was inconspicuous. Dr. Jameson had investigated the life-history of this parasite, and found that it arose as a tail-less Cercarian larva, in sporocysts, in Tapes decussatus and Cardium edule. He had succeeded in infecting Mussels from Tapes in an aquarium. The adult stage of this parasite was apparently Distoma somatinæ, Levinsen, which occurs in the intestine of the Eider-Duck, and which the author had found in the Scoter or Black Duck (Œdemia nigra). The complicated life-history of the parasite, and the absence of organs of locomotion in the Cercaria-stage, sufficed to account for the anomalous and hitherto inexplicable distribution of pearl-bearing Mussels. Dr. Jameson had found that pearls were caused by similar parasites in several other species of Mollusca, including some of the Pearl-Oysters; and he believed that the artificial infection of the Pearl-Oysters could be effected in a similar manner to that which he had found successful in the case of the Common Mussel. When this was achieved the problem of artificially producing pearls would be solved.

 

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Slowly but steadily the great collection of British Birds by Mr. F. Coburn, the well-known taxidermist, of Birmingham, is being built up. More than ten years have elapsed since the work was first entrusted to him by Mr. Baylis, of Birmingham, and it may be fifteen or even twenty years before the great task is completed. The statement suggests dilettante efforts, but, as a matter of fact, hard constant work has been given to the undertaking, and an enormous amount still remains to be done. The root idea is to prepare a collection of every species of British bird. This in itself does not appear a very formidable task, since there are only about 415 different kinds. But it is stipulated also that each bird should be presented at every stage of its existence, from the egg to the adult male and female, and, moreover, should be placed in a scene resembling its natural habitat. This means, of course, that the number of different birds which have to be collected and stuffed amounts not to hundreds but to thousands, and with no two alike. Take, for example, the Yellowhammer. In the first place, Mr. Coburn found a Yellowhammer's nest in a wild rose tree. Then, with incredible patience, he set to work, and patiently reproduced that scene in a case about five feet by three feet, with a depth of two feet six inches. The branches, twigs, and leaves of the tree were all faithfully imitated, and, as twenty-three gross of leaves were required, and each had to go through eleven distinct processes, the task was almost comparable with that of Sisyphus. But when that was finished, the real work had only begun. Just as the would-be cook is instructed first to catch his hare, so Mr. Coburn had to provide himself with Yellowhammers in every stage of development. Moreover, the adults vary considerably, so representatives of different types were included. Altogether, fifty specimens were necessary. Then each bird had to be stuffed—and in a collection on the lines indicated this is a matter requiring the most exact knowledge, as well as careful workmanship. Finally came the arrangement of the birds in the case. One nest containing eggs was fixed in the bush. As Yellowhammers build also on the ground, another nest was placed there, containing young. A bird just out of the nest, with its beak open to receive food from a parent close by, was the next object of attention. Then on the twigs of the bush were displayed the remaining birds in their different stages, and also the adults in characteristic attitudes. When, ultimately, the case was completed, Mr. Coburn had the satisfaction of knowing that he had disposed of one species.

At the present time forty species have been completed, and material has been collected for more than 250 of the remainder. For some birds—such as the Great Northern Diver—three separate cases are needed, and for the Heron there are two cases, each five feet wide and four feet six inches high. Of course, when the collection is completed it will be absolutely unique. It is declared that it will take absolutely the first place in the British ornithological world, easily surpassing the most famous collections of to-day. Certainly a very large hall—comparable in size with the Birmingham Town Hall—will be required in which to display the cases, and from the museum thus formed the life-history of every British bird can be deduced more readily than from acres of printed matter. At present large photographs of the cases are being taken, and probably, when about one hundred are available, they will be published in book form. In view of the magnitude of the task before him, Mr. Coburn sometimes speaks despairingly of the prospect of completing it. But it is to be hoped that more rapid progress will become possible in the future.—Birmingham Daily Mail.

 

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Alas! poor Heron. We extract the following paragraph from a weekly contemporary:—"The Heron does not seem to be a popular bird with proprietors of Trout streams. One gentleman has the following recipe for getting rid of the luckless feathered fisherman: 'Bait a night-line with a Trout threaded from head to tail with a long needle, leaving the points of the hooks outside the corners of the Trout's mouth. Attach the bait to a night-line, pegged down securely, and put the lure into the water on the shallow where the Heron comes to feed. If the line is properly leaded to keep the bait in position, you will have your Heron to a dead certainty, and can lead him home like a dog on a chain next morning.'" We commend this information to the Society whom it most concerns.