Referate 143

aber es sollte doch hierbei die Bedingung erffillt seth, daft die aufeinander- folgenden Anschauungen zu einem einheitlichen Ganzen verschmolzen stud.

Referent wtirde wohl der letzte sein, die Wichtigkeit der lipoiden Membran zu verneinen; aber die einfache Erwahnung der alten O v e r t o n - schen Theorie genfigt doch nicht. Die abweichenden Permeabiliti~tsverh~ltnisse der Tumorzelle sind mit quantitativ exakten Methoden schon l~ngst yon C l o w e s , W a t e r m a n und neuerdings von Morse bestimmt worden.

Zusammenfassend l~ifit sich sagen: ein Buch, worin viel Interessantes und Anregendes in einer nicht sehr harmonischen Form zu finden ist.

N. W a t e r m a n (Amsterdam).

Lepeschkin, W. W.: Morphologische Eigentiimliehkeiten der roten Blutk~rperehen im Lichte der Kolloidchemie. Biologia Generalis, 1,654--673, 1925.

The literature on the properties of erythrocytes is prolific with extra- ordinarily little agreement on some very fundamental facts. Only recently has there been a general understanding as to apparently so easily established a fact as the form of the human red blood cell. LEPESCHKIN has added valuable data to a subject in which exact work is needed. The corpuscles of the frog, horse and man were used as material.

I t is unfortunate that the terms "foam" (Schaum) and "emulsion-jelly" (Emulsionsgallerte) have been used by LEPESCHKm in reference to protoplasm. These terms carry with them the idea that hydrophilic colloidal jellies are foams or emulsions. This conception has now been fully discarded by leading chemists and never was accepted by such workers as ZSmMONDY, DUCLAUX und DONNAN. In biology the terms, and what they connote, still, unfortun- ately, persist. The properties of foams and emulsions are not the properties of colloidal jellies, and protoplasm belongs to the latter class.

The form of erythrocytes LEPESCHKIN believes is maintained by a semi- rigid membrane, and is not due to a gel consistency of the cell as a whole. The interior of the red corpuscle is liquid in nature. That the pellicle is somewhat pliable is indicated by the various shapes which the corpuscle assumes. Observations on blood cells with dark field (paraboloid condenser) substantiate the foregoing statement that the cell is surrounded by a pellicle; the corpuscle membrane is at least 1/2 ~, thick. These observations of L]~PESCHKIN are in full agreement with recent microdissection work on ery- throcytes (Protoplasma, 1, 345, 1926).

The corpuscle membrane when immersed in a 30/0 NaC1 solution be- comes liquid, often only in certain regions which causes the formation of globular protoplasmic protrusions. Ultimately, the entire pellicle goes into solution and the corpuscle assumes a fully spherical shape, which is proof of its liquid interior. The same phenomenon can be produced by immersing the blood cells in water. Haemolysis follows and a very delicate membrane is left behind. This is the "ghost cell" often referred to. LEPESCttKIN believes that this ghost cell is not the original membrane of the corpuscle, nor does it represent the stroma of the cell. On the contrary, the ghost cell is a secondary product, probably an adsorption membrane formed after the original membrane has gone into solution. This interpretation of the ghost cell is quite new and unique, and probably will not be fully accepted by all workers.

144 Referate

The physical state of the nucleus of the frog erythrocyte LEPESCHKIN believes to be liquid with a definite nuclear membrane. The presence of Brownian movement of particles which are gathered close to the inner surface of the nucleus is believed to be proof of the liquid nature of the nucleo- plasm. Brownian movement of particles in a heterogeneous system is not always conclusive proof of a liquid nature. MAST (Journ. Morph. and Physiol., 41, 347--425, 1926) has observed active Brownian movement of particles in Amoeba (the particles being in minute vacuoles) although the cell protoplasm as a whole is of gel consistency. Microdissection work (1. c.) on erythrocytes indicates a very high viscosity of the nuclear material and extraordinarily great elasticity. I t is quite possible that the nucleus undergoes changes in consistency, as does all protoplasm, and that LEPESCHKIN observed one of the degrees of viscosity which the nucleoplasm may assume.

The nuclear substance is, according to LEPESC~KI~, made up of two primary phases, the one a dispersed "granular" phase (microscopically visible), and the other the dispersion medium (microscopically structureless). The "granula" to which LEPESCHK~N refers is the dispersed phase of the protoplasmic emulsion, and the "ground substance" is the hydrophilic colloidal jelly which gives to protoplasm its high elastic qualities.

The immiscibility of protoplasm in water LEPESCHKrN believes to be proof of the fact that water is not the dispersion medium of the living substance. That protoplasm is immiscible in water is certainly true, but this property may be due to the internal cohesive force of the (probably fibrous) structural units of the living jelly, just as is true of gelatin which is likewise immiscible in (cold) water even though its dispersion medium is water. LZPESCHKIN believes that the dispersion medium of protoplasm is a loosely organized organic liquid.

WILLIAM SEIFRIZ (Philadelphia).

Kiister, E.: tJber vitale ProtoplasmafKrbung. (Zeitschr. f. wissensch. Mikro- skopie, 43. Bd., 1926. - - Kleine Original-Mitteil.)

Der Verf. berichtet fiber gelungene Vitalfiirbungen von Plasma und Zellkernen der Zwiebelschuppen (Allium cepa), wobei die yon Ki is t~r fiir verschiedene andere zellphysiologische Studien wiederholt mit Vorteil heran- gezogene Sorte ,,Zittauer Gelbe" sich als besonders geeignet erwies. Relativ starke LSsungen yon 0,1--0,2 g Erythrosin oder Eosin pro Liter Wasser er- gaben die besten Erfolge. Die Farbstoffaufnahme geschah yon kleinen, durch Nadelstiche verursachten Wunden, nachdem die gauze Zwiebel in die LSsung tibertragen wurde; nach e twa sechs Stunden war der Effekt im Dunkelversuch maximal. Daft die diffuse Fi~rbung wirklich vital war, wurde yon Ki i s t e r eindeutig sichergestellt, die bemerkenswert lange Lebensdauer gef~rbter Zellen (drei bis vier Tage nach Beginn der F~rbung) l~t~t auch keinen Zweifel darfiber aufkommen. Ausdrficklich hervorgehoben wird das Aussehen der gefiirbten, hyalin bleibenden Kerne, deren Farbenintensit~t yon der Wunde weg ab- nimmt, ferner die oft merklich intensivere Farbstoffspeicherung des Plasmas im Vergleich zum Zellsaft und schlietMich das Versagen der Fi~rbung in einzelnen F~llen trotz der zahlreichen positiven Befunde. - - Zu dieser kurzen Notiz yon K f i s t e r miJchte der Ref. folgende Bemerkungen mac-hen: 1. die Tatsache, daft die an die Wunde unmittelbar angrenzenden Zellen sich am st~trksten mit zwei so ausgesprochen sauren Farbstoffen f~rben, legt den Ge- danken nahe, daft man bei Erkl~rungsversuchen auch die Ergebnisse yon