Page:Science vol. 5.djvu/459

 L culture would be n more perfect knowledge of embry- r vitigj, of the physical conditions of tbe waters, and T the Influence of temperature upon the movements of I ttih. etc.

Mr. W. Y. Cox gave the audience a ' Glanee at Billingsgate,' itescribitig the location and general ar- rangement of thia celebrated fish-market, and the daily methods of transacting buBiness. He called attention to the fact that there was a great need for the Introduction of a system of cold storage similar to that employed in the United Slates.

Mr. Fred. Mather gave an account of hia work at Cold Spring Harbor. Statistics were presented show- ing the numbers of the various species hatched out under his direction, and a brief explanation as to his methods of operation was added.

Mr. Eugene S. Blackford read a paper on the oyster- beds of New York, containing a very instructive account of the present condition of the oyster indus- try of New York, In the eourae of his remarks, it was made to appear that the supply of oysters was much greater at present than tea or twelve years ago, and that, by a careful conttnaance of the methods of proteetion and planting, there was not the slightest douht that the most successful oyster industry in the world would become developed In the waters of Long Island Soimd.

Mr. John A. Ryder presented a paper on some of the protective contrivances developed by, and in con- nectiou with, the ova of various species of fishes. Ue clasaifled the eggs of fishes into four divisions, — ■ buoy- ant,' 'adhesive,' 'suspended,' and 'transported;' this last including such eggs as are hatched in the mouth, or in receptacles especially developed on the outside of the abdomen, or under the tail of the parent fish (usually the male), such as are hatched in nests built by the males, or are viviparously developed In the ovary or the oviduct of the mother. The e^ of the cod was the type of the first division, buoy- ant, but without an o!l-<]rop. The egg of the Spanish mackerel, bonito, eusk, and many other marine fishes. Is buoyant, and with an oil-drop opposite the germinal pole, where the embryo develops. The second group was represented by the e^ of the goldfish, which adheres singly to plants and weeds. The blennles lay eggs in radiating, adherent groups. The gobies, gobieso, yellowpeids, and many other forms, belong to this group. Aa an example of 'suspended' eggs, he referred to the common oviparous ray, which has four fllnmentous horns, one at each corner, which wind around plants, and suspend the eggs to weeds; so that as the tide sweeps by these horns, which have openings in them, fresh water is carried into the egg- case to aerate the embryo, and favor its incubation. In the Scombresocidae the entire egg-membrane Is covered with strong filaments, which Intertwine with those of contiguous eggs; and thus masses of eggs are suspended, sometimes several inches in lengtli. The Apelies, or fourspitied stickleback, was cited as an example of the fourth group. The male has a pouch on the right side of the rectum, from which is poured out a viscid secretion, and which Is spun out into threads fitfully by the animal, as he goes round a

��bunch of waterweedi', tike a bobbin, t« build a little ba.>ket-like neat for the eggs. Callichlhys also build* a nest, while Antennarius and fishing-frogs of the deeper ocean deposit their eggs on masses of sar- gossa-weed. Reference waa made to the numl>er of aalraonoids that prepare beda for the better protection of iheir eggs. This was also done by the black bass, sun-perch, and lampreys.

Prof. O. T. Mason, in a paper describing the use of the tb rowing-stick by the Eskimo In fishing, said that the must interesting of modern ethnological studiias is the tracing of human arts from their birth through the different stages of their evolution. Many savage devices live on In civilisation; but there is one, the Eskimo th rowing-stick, which is not only one of the most ingenious of aboriginal devices, but one which has not survived in more highly cultured peoples. An account was then given of the manu- facture, use, and distribution of this implement.

Professor Theodore Gill presented a paper entitled 'The chief charncieri sties of the North -American fish fauna.' He restricted his remarks to the fresh- water forms alone. He described America north of Mexico as a primary, lerrestrial-aqualic realm, vari- ously designated as the North -American, nearctic, and Anglogaean region or realm. It is one of the very richest in fresh-water types, more than six hundred species living exclusively, or nearly so. In the riverg and lakes. These species represent a hundred and fifty genera, and about thirty-five families. The Nortli-American fish fauna may he segregated Into two primary categories: 1°, arclogaean, including those families which are shared with Europe and northern Asia; and. 2°, those peculiar to this con- tinent, which are the Amildae, Hyodontidae, Percop- sidae, Amblyopsldae, Aphredoderidae, Elassomidae, Centrarchidae, and several sub-families, as the Ethe- ostominae, Hoplodinollnae, and Hysierocarpinae. Of the fresh-water species and genera of most of the families, some are anadromous; others Inhabit salt and fresh water almost in differently; and still others are catadromous, as the eet, which appears to breed only in the sea. The number of genera common to Europe and North America is extremely small. It 1< noteworthy that the number of the types peculiar to America are distinguished by the care which the parenU take of their young, whereas the European forms are generally IndlSerenL The care of tha eggs and young seems to be aceompanted by an apparent diminution of the number of eggs; and in Ihia respect there Is a kind of analogy between fish- culturlsls and parents. The fish-culturists assume the lurt which, in nature, Is exercised by the atten- tive parent; and the eggs and young, being provided for, stand less danger of destruction, and conse- quently in such the ratio tietween the eggs laid and fertilized, and the young matured, is very much less than that between the number of egg* of indifferent parents, and that of other progeny matured.

On Thursday, at noon, the members of the society, through the courleay of Professor Baird, went on the U. S. flab-commlssion steamer Fish-hawk, for a trip down the Potomac Hirer, to visit the shad-hatchlnp

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