Miscellaneous. 101 



mentioned reagents ; their membranes behave like proteine com- 

 pounds. These highly albuminous cellules form a continuous layer 

 on the inner surface of the tissue-cell-membranes, whilst a crystal- 

 loid floats in the ceU-fluid within this layer. New cells originate in 

 both kinds of content-cellules ; in the crystalloids only one or two, 

 which sometimes grow forth above the surface of their lameUiform 

 mother cell (like twin or triple crystals), while in each of the 

 numerous proteine-cellules numerous new cellules make their ap- 

 pearance, some of which grow into chlorophyl- vesicles. 



The free, highly albuminous cells which form yeast may be seen, 

 under certain conditions of nutrition, to acquire the tabular form, 

 as was pointed out by Karsten in his recent work, ' Chemismus der 

 Pflanzenzelle' (Vienna, 1869). These tables then resemble that 

 well-known ceU-form which has been regarded as a plant, under 

 the name of Sarcina, since Goodsir's time, but which, according to 

 Karsten and my own observations, belongs to the yeast series. 



Many alkaloids (for example, theobromine in the fruits of the 

 cacao-tree) likewise appear to be crystallized metamorphoses proceed- 

 ing from proteine-vesicles. Karsten is also inclined to ascribe the 

 same origin to the carotine in the root of the carrot {Daucus carota), 

 and to arrange it with the crystalloids of the lupine. He also 

 thinks that all the alkaloids and the nitrogenous glycosides (such as 

 amygdaline, myronic acid, &«.) are in like manner chemically me- 

 tamorphosed membranes of young cells (sap-vesicles) previously 

 consisting of proteine materials. The alkaloids he regards as simi- 

 lar bodies, which, generally combining with organic acids produced 

 at the same time from the membranes of the tissue-cells, may be 

 called acid salts, which consequently dissolve in the cell-sap. — 

 Die Natur, 1871, p. 323. 



Anatomico-zoologiml Remnrls upon Oncidium celticum, Cuvier. 

 By M. L. Vaillant. 



The presence on the French coasts of the curious Gasteropod 

 mollusk designated, since the time of Cuvier, by the name of Onci- 

 dium celticum is a well-known fact : nevertheless it appears to have 

 been but rarely met with ; for, since it was mentioned by M. Milne- 

 Edwards in 1828, it has not, I believe, been indicated in any cata- 

 logue. It is only in England that it has been described in a com- 

 plete manner. We may, however, be surprised that so interesting 

 an animal has not given rise to any thoroughgoing investigation, 

 and that the only attempts to make known to us its anatomical 

 organization, first by Cuvier (in 1804), and quite recently by Kefer- 

 stein (in 1868), wei'e made upon individuals preserved in spiiit. 

 The size of these species presented some facilities which do not exist 

 with that of our shores, the extreme dimensions of which are 

 scarcely more than 3 centimetres ; but all anatomists know that a 

 great number of important details can only be properly studied in 

 the fresh animal. In order to try to fill up this gap I have under- 

 taken a series of investigations, of which I here desire to give the 

 principal results. 



