1876.] Botany. 45 
to a depth of twelve feet. Some of the löss was taken with necessary 
precautions, and securely sealed until the Kta spring (1865). In 
May, twenty-four flower pots were half-fille manure which had 
been heated in order to destroy any seeds aai and on this substra- 
tum some of the löss was placed, leaving an air space above, of two 
inches, and each pot was covered by a glass disk which had a bit of 
wood under one edge to allow access of air. The surface of the löss” 
soon had plenty of ferns and mosses, just like those which are so 
abundant in all greenhouses. A few phenogamic plants came up; four 
which could not be determined accurately were suppdsed to be Vaccinium 
myrtillus, a second, a Chrysanthemum Leucanthemum ; afterwards a third 
came up, a Galium, and finally an Equisetum. A second series of exper- 
iments, conducted with greater care fo exclude all waifs, gave wholly 
negative results. Some molds, a coat of moss, and a single grass, Festuca 
pratensis, were the only plants within the bell-jars. R 
THE PRIMORDIAL UTRICLE. — Professor Pfeffer has lately studied 
the so-called primordial utricle, with the following results, which are given 
in the Botanische Zeitung, October 1st, from Kölnische Zeitung, 1875, 
248. Protoplasm placed in contact with aqueous solutions becomes 
clothed on all sides with a delicate membrane caused by precipitation. 
This is the so-called primordial utricle. In protoplasm, certain albumi- 
noids are dissolved, which separate out in water because their solvent 
is withdrawn. But this is limited to the surface of contact, because 
the membrane formed by precipitation does not allow the solvent to 
pass through. What this solvent is, has not been ascertained positively, 
but it is believed to be something beside the inorganic salts which, in 
egg-albumin, hold a protein substance in solution. 
RIGIN OF HIGH HYDROSTATIC PRESSURE IN VEGETABLE CELLS. 
— In the Botanische Zeitung, November 5th, there is an abstract of a 
communication made by Professor Pfeffer to the botanical section of the 
Association of German Naturalists and Physicians, at Graz, 1875, on the 
subject of the origin of high hydrostatic pressure in vegetable cells. 
This pressure, amounting sometimes to seve atmospheres, even where 
there is only slight concentration of the fluid contents of the cells, led 
him, on theoretical grounds, to refer it to the molecular condition of the 
Primordial utricle. ‘Chis conclusion was confirmed by experiment. With 
contraction of the molecular interspaces, resistance to filtration increases, 
and likewise the pressure which is brought about endosmotically. Thus 
in the case of the precipitated membrane of ferrocyanide of copper (see 
Sachs’s Text-Book, p. 597) a pressure of two atmospheres can be ob- 
tained, provided the film finds a suitable support, in a two per cent. solu- 
tion of cane sugar. In the brief account given, there are no details as 
to the method of determining the amount of pressure. The resistance 
of the membrane to filtration is a complex force dependent on several 
Variables, but with changes in this resistance, hydrostatic pressure is 
