OCR Text |
Show 124 DR. J. E. GRAY ON HYALONEMA LUSITANICUM. [Jail. 24, the polypes (which equally cover the axis in both cases) in the other -that is to say, in two genera of the same family ? Some of the siliceous spicules found in the inner layer of the bark of the axis or coil of the Japanese species are similar in form to those which are found in the sponge on which it grows (see Schultze, t. 3. f. 11-14 ; Brandt, t. 3. f. 15, 16)*. They differ from the spicula in the sponge in being smaller in size, stouter, and more spinose; but when you see the very variable forms the spicules of the sponge assume, and how the forms blend into each, as well shown by Schultze, t. 1. f. 3, 4, the passage from the spicula of the sponge to those of the bark can easily be believed by a casual observer ; but those of the bark and of the sponge each keep their own peculiar form and position, and are never found intermixed. Some microscopists, who frequently pay little attention but to the " microscopic object," and therefore take a narrow view of the affinities of animals, place great reliance on this similarity of the spicules of the polypes and the sponge, and regard them as the same. This would have weight, if the perfect organization and development of the polypes did not prevent m e from accepting Dr. Bowerbank's theory that the bark is part of the sponge. But, admitting as we must that the coil is covered with well-developed polypes, the existence of these cruciform or subcruciform spinulose spicules does not offer us any assistance to discover whether the polypes are parasitical or are the makers of the coil; and they have been observed by the advocates of each theory, as above quoted, only so far as one may argue that, if the polypes develope these cruciform siliceous spicules and also cylindrical ones in the bark, there is less difficulty in believing that they also develope the siliceous filiform spicules of the coil or axis. Dr. William Lockhart states that the Japanese Hyalonema is found growing on the rocks off the island of Enosima, near the old capital Kamakura, and not far from Yokohama. The fishermen offer these sponges with their siliceous fibres for sale to visitors at the temples of Enosima. The Japanese are intelligent and patient people, and they manufacture many articles of the coils of spicules of this coral. They sell them with one or more bands of coloured or gold paper put round them to keep them together, or they enclose the narrow base of the coil with spiral strips of paper, strips of cloth or ribbon, forming them into an aigrette; these are prepared for the general market. Oddly enough, when they, or some of the fishermen, must have stripped the bark off the coil, they prepare others evidently for the more scientific purchasers. Thus I have seen a specimen which had the thin lower end of the coil enclosed in a spiral band of paper covered over with a coil of string having knots at certain distances. This was all covered with sand and minute particles * Professor Brandt considers the spicules to belong to different species calling the one at the base Spongia octancyra (p. 14), and the other in the bark Spongia spinicrucis (p. 23). |