1904] CURRENT LITERATURE ee 
vigorous that it completely excludes other characteristic and conspicuous 
marsh plants, such as the tule and cat-tail—J. M. C 
RALPH E. SMITH” has issued a preliminary report of his investigation of 
the asparagus rust, a disease which is seriously threatening a great Californian 
industry. A complete account will be published later, but the interests 
involved demand such current information as is available. The account is 
clear and to the point, and the practical suggestions are of great value, but 
the wretched half-tone illustrations are almost like so much waste space in 
so far as they are intended to show anything distinctly.—J. M. C 
MARIANI, in a study of the influence of humidity on the development of 
stomata in the cotyledons,?" seems to have obtained no very decisive results. 
He found that in light humidity tends to increase the area of the cotyledonar 
limb, but to diminish the number of stomata and (rather more) the number 
of epidermal cells per unit of surface, which is as much as to say that it 
favors the formation of stomata, but does not augment their number. Jn 
darkness the reverse effect appears, but even less distinctly.—C. B 
TIL VERY recently there has been no evidence that the Carboniferous 
ferns followed the same course of development as their recent allies, Within 
a few months a fossil sporangium, collected by Mr. J. Lomax, has been sec- 
tioned by D. H. Scott“ and found to contain germinating spores of a quite 
modern type. The rhizoids in several specimens are perfectly clear, as are 
the cell divisions of the young prothalli. The sporangial wall in its multi- 
seriate structure resembles those of the eusporangiate ferns.— FLORENCE 
YON 
BRIOSI AND FARNETI® have investigated the lemon scab found in Italy, 
which has recently appeared in Sicily, where the natives call it ruggine 
bianca. They have identified two diseases due to the presence of a poly- 
_ morphic fungus known variously as Rhynchodiplodia, Cladosporium, Hormo- 
dendron, Ovularia, Haplaria, Pseudofumago, an Pseudosaccharomyces. 
, patie : . 
SMITH, RALPH E., Report on asparagus rust investigation. Agricultural 
Experiment Station, University of California, Circular no 9, January 4, 1904. 
* MARIANI, GINDITTA, Intorno all, influenza dell’? umidita sulla formazione e 
sullo sviluppo degli stomi nei cotyledoni. Atti Istituto Bot. Univ. Pavia 11. 8: 67- 
98. 1904. 
22 Scott, D. H., Germinating spores in a fossil fern sporangium. New Phytolo- 
gist 3: 18-23. 1904. 
23 Briosi, G., and FaRNETI, R., Intorno alla ruggine bianca dei limoni, grave 
malattia manifestatasi in Sicilia. Atti Istituto Bot. Pavia 10:—. 1904. 
