332 BOTANICAL GAZETTE [OCTOBER 
Euchiaena and maize are rather closely related to one another, and cross 
spontaneously. Seed of the former imported from Mexico is often obviously 
hybridized. That from Durango, whence Cotttns and Kempton got their 
strain, is so impure that the parent of their hybrid is not free from suspicion 
of contamination. A priori, therefore, we should expect similarity of behavior 
in the hybrids between these two closely related plants and the distantly 
related Tripsacum. Nevertheless, all the plants of TripsacumX Mais thus far 
raised have shown maternal characters only, in marked contrast to the paternal 
characters of the corresponding hybrid TripsacumX Euchlaena. More first 
generation plants are greatly to be desired, but there is difficulty in getting 
them because the parent species can seldom be brought into flower 
simultaneously. 
The authors lead us to expect cytological data bearing on the question 
raised by their very important discovery —H. H. BARTLETT. 
Negative osmosis.—In osmotic experiments it has been found that the 
flow of water is not always from the less concentrated toward the more con- 
centrated solution. Several cases have been reported in which an opposite 
flow of water occurred, or in which a movement of water was observed in 
dealing with solutions with the same osmotic pressure. This is called negative 
or abnormal osmosis. FREUNDLICH” has given us a discussion of these experi- 
ments, has defined the conditions under which abnormal osmosis can take place, 
and has dealt with the cause of it. It appears that such movements of water 
are caused by the development of an electric current through the membrane, 
and the water moves in an electroendosmotic manner in the current. The 
generation of this current and the consequent electroendosmosis can take 
place in two sets of conditions: (1) when the membrane is permeable to both 
solvent and solute the ions of the electrolyte are adsorbed by the membrane, 
their transport numbers changed, and a difference of electric potential on 
opposite sides of the membrane established, which leads to the starting of an 
acro! 
This can take place only when the electrolytes on opposite sides of the mem- 
brane are different and are such that the ions may react with each other and 
set free electrical changes.—F. E. DENNY 
Growth in Laminariaceae.—Miss FALuts** reports experimental data on 
the growth of several species of Laminariaceae. She worked on species of 
Laminaria, Agarum, Cymathaere, Egregia, Alaria, and Nereocystis. She found 
2 FREUNDLICH, H., Uber abnorme Osmosen. Kolloid. Zeitschr. 18: 11-16. 1916. 
2 Fatiis, ANNIE L., Growth in some Laminariaceae. Puget Sound Marine Sta. 
Publ. 1:137-155. pls. 25-28. 1916. 
