ZOOLOGY AND BOTANY, MIOBOSCOPY, ETC. 
805 
Fragments removed by artificial division from a Stentor in the state 
of conjugation are regenerated when the joints of the nucleus which these 
fragments contain still present a clear and homogeneous appearance, 
which is a sign of their vitality. In the more advanced stages, when 
these joints are greyish and granular — a sign of their approaching dis- 
integration — the fragments are not regenerated. After a certain time 
the pieces which contained them degenerate and die. At the same time 
these fragments regain the power of regeneration when a new nucleus 
makes its appearance in the protoplasm. The author thinks that the 
experiments he relates show clearly the physiological influence of 
conjugation. 
Nutrition of Trichosphaerium.* — Herr F. C. Noll observes that in 
his aquarium Trichosphserium Sieboldii Schn. feeds on diatoms, clearing 
small areas on the surface of the glass. On such places the Rhizopod 
multiplies rapidly. 
Structure of Peridinidse.f — Dr. F. Schiitt distinguishes a cortical 
plasma [THillplasma) from an internal plasma ( Fullplasma ). The 
former includes a hyaline layer and a granular layer. Within the 
granular layer are various kinds of bodies, notably minute plate-like 
chromatophores, fat-plates, small rods, bundles of threads, and plastids 
which are probably fat-formers. The internal plasma includes no 
granular bodies, but a nucleus, sap-chambers, and a vacuole-apparatus. 
The latter includes a large sac-vacuole with an efferent duct, a smaller 
collecting-vacuole also opening near the flagellum-cleft, minute daughter- 
vacuoles which surround the collecting-vacuole, and fourthly, but 
exceptionally, diffuse accessory vacuoles. No pulsations were observed, 
but it is likely that the daughter-vacuoles empty their contents into the 
collecting vacuoles. “ Collecting- and sac-vacuoles are morphologically 
equivalent organs,” without homologues in the cells of higher plants ; 
the sap-chambers are quite distinct from the vacuoles and correspond to 
the sap-cavities in plant-cells. 
Argentine Gregarinida.J — Prof. J. Frenzel describes five new 
species, Gregarina statirse , G. bergi, G. panchlorse , G. blaberse, and 
Pyxinia crystalligera , but the interest of his communication is chiefly 
physiological. By microchemical analysis he distinguishes the follow- 
ing substances : — (1) Protoelastin, the substance of the cuticle 
and perhaps of the epimerite membrane, of the partition, and of the 
nuclear wall ; insoluble in acetic and nitric acids, alcohol, ether, 
chloroform, &c. ; soluble more or less in alkalies ; altered into a non- 
elastic substance by acetic acid ; for the most part insoluble in saliva, 
but digestible. (2) Alveolin, the substance of the mesh-work ; insoluble 
in acetic, sulphuric, and nitric acids, caustic potash and saliva ; fixed by 
alcohol, corrosive sublimate, &c. ; stained by carmine ; not exhibiting 
iodine reaction. (3) Paralveolin, accompanying alveolin, but soluble 
in saliva, acids, and alkalies. (4) Neutral fat, in drops, especially in the 
protomerite. (5) Albuminoids, some fixed by corrosive sublimate, 
others also by acids. (6) Protocollagen, swelling in acetic acid and 
* Zool. Anzeig., xv. (1892) pp. 209-10. 
f SB. K. Preuss. Akad. d. Wiss., 1892, pp. 377-83 (1 pi.). 
X Jenaische Zeitschr. f. Naturwiss., xxvii. (1892) pp. 233-336 (1 pi.). 
