F. F. Blackman. 
i Bo 
THE 
PLASMATIC MEMBRANE AND ITS ORGANISATION. 
By F. F. Blackman. 
F. Czapek. ‘‘fiber Fallungsreaktionen in iebenden Pflanzenzellen und einige 
Anvvendung derselben.” Ber. deut. bot.Ges., Bd. XXVIII, 
1910, pp. 147-159. 
,, “ Versuche liber Exosmose aus Pflanzenzellen.” Ibid, pp. 159— 
169. 
,, “ Uber die Oberflachenspannung und den Lipoidgehalt der 
Plasmahaut in Iebenden Pflanzenzellen.” Ibid, pp. 480—487. 
,, “ Uber eine Methode zur direkten Bestimmung der Oberflachen¬ 
spannung der Plasmahaut von Pflanzenzellen.” Jena, Gustav 
Fischer, 1911, 86 pp. 
W. W. Lepeschkin. “Zur Kenntniss der Plasmamembran.” Ber deut. 
bot. Ges. Bd. XXVIII, 1910, pp. 91—103. 
,, “ Zur Kenntniss der Plasmamembran. II,” Ibid, pp. 383 — 393. 
,, “ Zur Kenntniss der chemischen Zusammensetzung der 
Plasmamembran.” Ber deut. bot. Ges., Bd. XXIX, 1911, 
pp. 247—260. 
,, “ Uber die Einwirkung anaesthesierenderer Stoffe auf die osmot- 
ischen Eigenschaften der Plasmamembran.” Ibid., pp. 349 
—354. 
I T has long been recognized that the surface-layer of any mass, 
whether solid or liquid, differs somewhat in physical pro¬ 
perties from the internal parts of the mass. This physical 
difference is of course related to the fact that the molecules of 
the surface-layer have molecules of their own nature only upon 
one side of them, and they are therefore in a different environment 
from more centrally situated molecules, as regards the distribution 
of the inter-molecular forces. 
This general principle applies also, of course, to the mass- 
units of living things, the individual protoplasts and indeed very 
special properties, for example in the matter of selective per¬ 
meability, are generally attributed to the “ Plasmahaut ” or 
surface-layer of the protoplast. 
It is very interesting to find two such trenchant investigators 
as Czapek and Lepeschkin now converging upon this same 
subject—the organisation of the plasmatic membrane—by two 
quite independent lines of work. After some general remarks upon 
the biochemical aspect of the matter, I propose to give a summary 
of the progress that has been made by each of these workers. 
