386 Miscellaneous. 



(jlorna), I call attention to this anatomical peculiarity, of whicli he 

 has given a detailed description in a memoir published in conjunc- 

 tion with M. L. de Sanctis. 



On examining at the bottom of the mouth the pharyngeal aper- 

 tures of the branchial chambers, or separating the walls of their 

 external apertures, we see, in front of each of the respiratory sur- 

 faces, a very regular series of organs which do not occur in any 

 other fish, whether bony or cartilaginous. I have ascertained that 

 they are wanting in two species belonging to genera nearly allied to 

 Cephaloptera (nameh^ Ithinoptera man/inalis and ^tobatis narhiari). 

 Thus their presence appears to me, as to M. Pauceri, to coistitute 

 one of the essential characters of the genus CephaJopteni. 



These organs are elongated lamellae, the aspect of which somewhat 

 reminds us of that of the stems of ferns, but with the leaflets turned 

 back towards the branchiee. Each being formed of a fold of mucous 

 membrane supported by a cartilage, these lamellae are attached to 

 the anterior surface of the branchial arches, in front of the mem- 

 branous and vascular folds of the respiratory organs ; and it is their 

 position that has suggested the name of prehranchiaJ appendages, 

 by which they are designated by the Italian anatomist. 



They do not serve for respiration. By means of injections, M. 

 Panceri has ascertained that they receive arterial vessels, like the 

 other organs, and not branches of the branchial artery. According 

 to him, they are destined, on account of the remarkable size of the 

 apertures of the branchial chambers, the orifices of which are much 

 smaller in the other Rays, to retain the water and prevent it from 

 traversing these cavities with a rapidity which would be injurious to 

 the perfect accomplishment of the act of haematosis, — Comptes 

 Rendus, March 7, 1870, tome Ixx. pp. 491, 492. 



Observations on the Turninr/ of Fungi. 



By M. P. DUCHARTRE. 



The author remarks that whilst the researches of modern bota- 

 nists have accounted for a great number of the vital phenomena of 

 plants, there are still some whose causes remain in obscurity, al- 

 though the phenomena themselves may be manifested daily to 

 observation. Among these are the phenomena of direction, the 

 tendencies of certain organs to hold themselves always in a parti- 

 cular position, and to reiurn to that position when designedly dis- 

 placed from it. The favourite hypotheses upon this subject, espe- 

 cially in Germany, tend to give the phenomena a ijurelj mechanical 

 character ; but the author contends that such generalizations have 

 been made too hastily, and cites the following curious instance of 

 the growth of a fungus under very peculiar circumstances in support 

 of his opinion. 



In a garden at Meudon (Seine-et-Oise) a cask had been placed to 

 serve as a reservoir for watering the garden ; it was a cask of 225 

 litres, having its bottom covered with a thick layer of plaster ; it 



