Miscellaneous. 69 interest: thus I have succeeded in tracing the mechanism of the sin-gular motions discovered by M. Sieboldt in the interior of the audi-tory capsule of the Mollusca ; I have convinced myself in the most positive manner of the existence of herraaphrodism in the Anatifcs, a fact which had been rendered doubtful by the observations of Mr. Goodsir on the alleged males of the Balani. I have observed that in the Haliotides the sexes are separated as in the PatellcB, and that consequently it is at present less possible than ever in my opinion to admit as the basis of classification of the Gasteropod Mollusca, the distinction of these animals into moncecious, hermaphrodite, and dioecious. I have discovered a new fact which shows how little physiological importance should be attached to the colour of the blood, so constant in the '\"ertebrata, in the inferior animals, a con-clusion which already resulted from my observations on the Vermes. I have found in fact, in the neighbourhood of Palermo, an Ascidia with red blood. I shall in conclusion notice another zoological fact which of itself is of no importance, but will furnish a further proof of the errors which might be committed by placing too much con-fidence in the invariability of the relations which appear to exist be-tween the organization of the lower animals and their external cha-racters. M. Savigny, in showing how much the internal structure of the compound Ascidice differs from those of the Halcyons and other polypes with which they had up to that time been confounded, pointed out the existence of six tentacula in the one and of eight in the others, as being the external character the most fit to distinguish them without the aid of the scalpel ; and in truth never more than six tentacula had hitherto been found round the mouth of the com-pound AscidicB, while the Halcyons and other zoophytes constructed after the same type, always present eight ; but this empirical cha-racter now loses its entire value, for I have found in the Mediterra-nean a compound Ascidia having eight of these appendages." The author promises to give an account in a future communica-tion of his observations on the development of the Annelida. From the Comptes Rendus for Nov. 25, 1844. OBSERVATIONS ON SOME POLYPES. Dr. Reid has detailed several new observations he has made upon certain polypes when carefully examined by the microscope : he men-tions some appendages to the polypidom in the Cellularia scruposa and Cellularia reptans which had not been previously described. At the antei'ior part of the outer side of each cell in the Cellularia scru-posa, and immediately in front of the tooth-like process there attached, are two pretty long spines and a rounded process, which tapers slightly from its fixed to its free extremity. This rounded process is open at the top, and is hollow in dead specimens : but when alive it is full of a contractile substance. In this contractile substance the end of a hair-like curved filament, about the length of the cell, is immersed. This hair-like filament is moved about by the contractile substance attached to it, generally in jerks after intervals of repose, and in its movements sweeps the anterior and posterior surfaces of
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