282 BOTANICAL GAZETTE [APRIL 
of the attraction. The results are tabulated according to De Vries’ obsolete 
isotonic coefficients, and in order to be studied need to be rearranged by 
base and acid. The small number of salts of any given acid makes it utterly 
impossible to draw any conclusion as to the nature of the attraction. The 
author’s propositions in this regard may or may not be substantiated later; 
several hypotheses might be formulated which would explain equally well 
the cases cited. It is unfortunate that this paper (following that of Garrey* 
by nearly a year) should carry our knowledge of this important subject of 
chemotaxis such a little way further than it was carried by that writer. We 
have tried, with some success, to coordinate the results given in these’two 
papers, but nothing definite can be attained, so far as fern sperms are con- 
cerned, until we have more data. Chemical principles must be brought into 
requisition in the selection of salts to be tested as well as in the interpreta- 
tion of results. The author makes an interesting observation with regard to 
starch grains in the vesicle of these sperms. During the swarm period the 
oxidized for the production of kinetic energy. Unhappily, no observations 
on the hydrolysis of these grains were made. We may suppose them to be 
converted into glucose by an enzyme formed in the vesicle. Thus we might 
have the non-nucleated cytoplasm of the sperm mother cell doing nutritive 
work for the moving sperm. This, if shown to be the case, might throw 
some light on the phenomena occurring in the male cells of the lower gym- 
nosperms.— BURTON EDWARD LIVINGSTON. 
AMONG RECENT CONTRIBUTIONS to paleobotany the following papers may 
be mentioned: Lester F. Warp (2oth Ann. Rep., U.S. Geol. Survey, 1900), 
with the collaboration of Fontaine, Wanner, and Knowlton, has published an 
extended account of the Triassic and Jurassic floras of the United States. 
The various areas are systematically treated, and much new material is 
incorporated. A large number of plates accompany the work, many of which 
illustrate Ward’s recently described genus Cycadella. A similar report on the 
Cretaceous is to be expected soon from the same source, and will be heartily 
welcomed, inasmuch as the literature is considerably scattered. Ward has 
also published a very interesting popular report on the petrified forests of 
Arizona, which has been issued by the United States Geological Survey.— 
F. H. KNowLTOon has published on the flora of the Montana formation (Bull. 
163, U.S. Geol. Survey, 1900); this together with his previous papers on fossil 
plants from Idaho and Yellowstone Park adds greatly to our knowledge of 
the late Cretaceous and early Tertiary floras of that part of the United States. 
— Davip Waite (2oth Ann. Rep., U. S. Geol. Survey, 1900) has worked out 
*SThe effects of ions upon the aggregation of the flagellated infusoria. Am. 
Jour. Phys. 3: 291. 1900. 


