1904] CURRENT LITERATURE 317 
subject are put under three categories: (1) axial theory; (2) foliar theory; 
and (3) sw generis theory, which means that the ovule is to be regarded as an 
independent structure, borne either on stem or foliar organs. The bibliogra- 
phy contains 149 titles under 82 authors.— J. M. C 
ug ARSTEN AND SCHENCK have issued three more numbers of their valu- 
3 able Vegetationsbilder*® The sixth number was prepared by Karsten and 
_ portrays the following tree monocotyledons: Pandanus, Zanthorraea, Yucca, 
_ Nolina, Dendrocalamus, Ravenala. In the seventh number Schenck illus- 
_ trates the strand vegetation of Brazil, giving several photographs of the Pes- 
E Caprae and Restinga formations. Karsten and Stahl prepared the eighth 
_ number, which treats of Mexican xerophytes. Excellent illustrations of cacti, 
_ agaves, and other desert forms are brought together. These numbers main- 
_ tain the high standard of the earlier parts, and it is more apparent than ever 
that this publication is of great practical value to all botanical libraries and 
_ laboratories.— H. C. CowLEe 
Erwin F. SMiItH AND DEANE B. SWINGLE”® have published the results 
of their study of the dry rot of potatoes. The “bundle blackening” and “dry 
end-rot’’ are found to be two stages of the same disease, which begins in the 
field in the underground stems and roots. A fungus, which has proved to be 
a Fusarium, is always present in the darkened vascular bundles of the tubers. 
The fungus tolerates large amounts of certain acids, as malic, citric, and tar- 
taric, and is inhibited by small amounts of others, as formic, acetic, and butyric. 
It attacks the plants from the soil and winters over in the earth, so that in land 
frequently planted to potatoes it can probably maintain itself indefinitely. 
Infected land should be planted to other crops for a series of years, and great 
care should be taken to avoid the infection of healthy land by planting dis- 
eased tubers.— J. M. C. 
MOLIscu, seeking to check Friedel’s and Macchiati’s results, which indi- 
Cate that photosynthesis is an enzymatic process,” reports experiments upon 
S€veral plants, using the luminosity of Mzcrococcus phosphoreus as a reaction 
for the evolution of oxygen (Beijerinck’s method, the sensitiveness of which 
ee Te PR sic ie te 
Sig Roy a oe 
2 
7 WORSDELL, W. G., The structure and morphology of the “ovule.” Ann, 
Botany 18: 57-86. 1904. 
%® KARSTEN, G., and SCHENCK, H., Vegetationsbilder. Hefte 6, 7, 8. pis. 31-48. 
ad: Gustav Fischer, 1903. Single parts AZ 4; to subscribers JZ 2.50. 
SMITH, ERWIN F., and SwWINGLE, DEANE B., The dry rot of potato due to 
Fusarium oxysporum. U.S. Dept. Agric., Bur. Pl. Industry, Bull. 55. pp. 64- AM. & 
Issued Feb. 16, 1904. 
* Reviewed in Bor, GAZ. 32:430- 1901; 33:315- 1902; 351226. 1903. 
