266 Miscellaneous. 



faces a zone which may be termed the nutritive zone of the acon- 

 tium ; in the immediate neighbourhood of the mesenterial filaments 

 — at the spot where the median swelling alone persists — the epithe- 

 lium of the septa exhibits a special development, which seems to me 

 to be in direct relation to the nutrition of these organs of secretion. 



These physiological facts appear to me to contribute towards 

 clearing up the origin of the convoluted filaments in ontogeny. 

 Heider *, relying on the identity of their histological structure, 

 admitted the ectodermic origin of the enteroids in Cerianthus, and 

 E. B, Wilson f considered it to be very probable that the lateral 

 lobes arc the homologues of the ectodermic bands of the Alcyonaria, 

 while in his opinion the central lobe is of an endodermic nature. 

 A, Andres % thought that he had succeeded in deriving certain fila- 

 ments of the Actiniaria from ectodermic proliferations of the 

 stomodseum. But it seems to follow, from certain observations of 

 H. V. Wilson §, that this ectodermic origin ought to be attributed 

 not only to the lateral lobes, but also to the median one, at the very 

 least in the case of the primary mesenteries. 



However it may be with regard to supposing, as appears to me to 

 be very probable, that the three lobes composing a typical filament 

 are of an ectodermic nature, it is not less probable that, relying on 

 the identity in histological structure and physiological function, we 

 ought to consider as endodermic the regions of the filaments which 

 separate the lobes from one another and the nutritive zone of 

 the acontia. — Zoologischer Anzeiger, xvi. Jahrg., no. 409 (January 9, 

 1893), pp. 10-12. 



On Phagocytosis observed, in the living Animal, in the Gills of 

 Lamellibranch Mollusea\\. By M. de Bruyne. 



In a communication of Nov. 3, 1891 (' Annales de la Faculte de 

 Medecine de Gand '), I mentioned incidentally some phenomena of 

 phagocytosis which had been observed in the normal ciliated 

 epithelium of the gills and mantle of Lamellibranch Mollusks ; 

 these observations related exclusively to fixed preparations. Since 

 then I have studied the phenomenon in the living animal, by 

 operating upon four very common forms — Mytilus, Unio, and 

 Anodonta, which are very suitable for this kind of observation, and 

 Ostrea, which is much less so, probably on account of the thickness 

 of its gills. 



If a fragment of gill be removed from a freshly opened specimen 

 of one of these animals {Mytilus by preference), and examined 

 under the microscope, the observer is struck by the clearness with 



* V. Heider, '' Cerianthus membranaceus" Sitzgsber. Akad. Wiss. Wien, 

 Bd. Ixxix. (1879). 



t E. B. Wilson, '' The Mesenterial Filaments of the Alcyonaria," 

 Mittheil. zool. Stat. Neapel, Bd. v. (1884). 



;[ A. Andres, quoted in the foregoing paper. 



§ H. V. Wilson, '' The Development of Manicina areolata,*^ Journal of 

 Morphology, 1889. 



II The investigations were conducted at the Laboratory of Normal 

 Histology of the University of Ghent. 



