Miscellaneous. 09 



interest: thus I have succeeded in tracing the mechanism of the sin- 

 guhir motions discovered by M. Sieboldt in the interior of the audi- 

 tory capsule of the Molhisca ; I have convinced myself in the most 

 positive manner of the existence of hermajihrodism in the Analifa:, 

 a fact which had been rendered doubtful by the observations of Mr. 

 Goodsir on the alleged m;Ues of the Bahini. I have observed that 

 in the HuUotides the sexes are sepjvrated as in the PatelUc, and that 

 consequently it is at present less possible than ever in my opinion to 

 admit as the basis of classification of the Gastcropod Mollusca, the 

 distinction of these animals into monoecious, hermaphrodite, and 

 dioscious. I have discovered a new fact which shows how little 

 l)hysiological 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 

 Avhich of itself is of no importance, but will furnish a further proof 

 of the errors which might be committed by placing too much con- 

 tidencc 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 Ascidice, while the Halcyons and other zoophytes constructed 

 after the same type, always present eight ; but this emj)irical 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. 



OBSKHVATIONS ON SOME POLYPES. 



Dr. Ileid has detailed several new observations he has made upon 

 certain polyj)es when carefully examined by the microscope : he men- 

 tions some apj)endages to the polypidom in the Celluhiria scruposa 

 and Cellulariu rcptans which had not been previously described. At 

 the anterior part of the outer side of each cell in the Cellidaria 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 



