478 BOTANICAL GAZETTE [DECEMBER 
complete vacuum against atmospheric pressure for a day or more. The tube thus 
prepared and connected to a two-liter vacuum chamber is placed in the soil to be 
studied. |The water surfaces of the pores in the tube become continuous with 
the surfaces of water films in the soil, and water moves into the tube at a rate 
which varies with the nature of the soil and its amount of contained moisture. 
The force involved in the movement of water through the wall of the tube is the 
difference between the capillary pressure or surface tension of the water surfaces 
at the external and internal ends of the pores of the wall. And since the external 
surfaces are continuous with those of the soil water, it follows that water must pass 
from the soil into the tube, for the soil films are subjected to a pressure of one 
atmosphere, while those at the internal surface of the tube bear a pressure only 
equal to the vapor pressure of water. The authors do not make this matter 
immediately clear, and it may simplify matters to call attention to the fact‘? that 
the films of tube and soil form a system one extremity of which (in contact with 
the vacuum) is subjected to a very low pressure, while the other extremity (in con- 
tact with the air) is subjected to a pressure relatively very great. Thus in the end 
the solution is driven through the tube by atmospheric pressure, though the steps 
in the movement involve the forces of capillary films. 
The rate at which water collects in the tube is the criterion for the soil’s power 
of delivery. The authors state that the nature of the collected solution is the same 
as that of the soil itself, though proof of this is reserved for a later paper.—B. E. 
LIVINGSTON. 
Errksson‘s has published two further accounts bearing on the mycoplasma 
theory of rust fungi. These accounts deal with Puccinia dispersa Eriks. on rye 
and P. glumarum Eriks. & Henn. on barley. The facts, according to the author, 
are these. The teleutospores of P. glumarum are capable of germinating imme- 
diately after ripening in midsummer. Aecidia occur on Anchusa arvensis and A. 
officinalis. During thirteen years’ observations the aecidia were observed only in 
three instances in the vicinity of Stockholm. Both because the aecidium is pro- 
duced from the teleutospores in summer or autumn, and on account of its rare 
occurrence in this region, it cannot be the source of spring infections of rye. It 
is also impossible to find living mycelium in the plants during the winter. These 
facts point to the conclusion that the infection arises from a germ already existing 
in the seed. In the leaves sectioned during the winter the author found peculiar 
dense protoplasm which he considers as a mixture of the protoplasm of the host 
and of the fungus mycoplasm. Later the nucleus is partially dissolved, while 
“nucleoli” begin to appear in the mycoplasm. ‘This stage occurs immediately 
42 This method of statement has been hinted at in a review of this article by KING. 
Either this reviewer has failed to grasp entirely the meaning of the authors or his own 
statements are so ambiguous as not to warrant a discussion of his criticisms here. See 
Kine, F. H., An artificial root for inducing: capillary movement of soil moisture. 
Science N. S. 20:680-681. 1904. 
43 ERIKSSON, J., Ueber das vegetative Leben der Getreiderostpilze. Kungl. 
Svensk. Vet.-Akad. Handl. 38:—. [no. 3. pp. 18.] pls. 3. 1904. 
