1911] CURRENT LITERATURE 157 
as the primary basis for the arrangement, thus leading to an association of 
genera-entirely different from that usually found in taxonomic works. By 
this method of classification, the genera of the Hypocreales and Dothidiales 
are distributed among the Sphaeriales. In the descriptions both the charac- 
teristics of the diseases and the life histories and characteristics of the 
causal organisms are given. The scheme is similar to that followed in the 
author’s Text-book, but the accounts are much more complete as to detail | 
eases. The older and better known facts receive full and careful treatment, 
but with regard to the newer facts of plant pathology, the work shows a 
of critical consideration of the literature which greatly impairs its value as 
a reliable reference book. A few instances illustrating this point may be 
cited. The rotting of lettuce in greenhouses is still attributed to Botrytis 
cinerea (Sclerotinia Fuckeliana) (p. 263), although the investigations of SmrrH3 
several years ago have shown that Sclerotinia Libertiana is the principal cause 
of this rot, while Botrytis-forms are only of secondary importance. These two 
fungi, although related, differ greatly in their mode of life, Botrytis being a 
common saprophyte everywhere, while S. Libertiana is a soil fungus. This 
great difference in the mode of life of the two fungi is of importance when 
methods of combatting them are considered. The wilt disease of cotton and 
other plants is described (p. 228) under Neocosmospora (misspelled Neocos- 
mopara in the page-heading, seach POE: and text, and still different in 
the index). A symptom of the same disease is described (p. 494) under its 
old name “Cotton Frenching,” caalid by Fusarium vasinfectum. The genetic 
relationship between these two fungi has been shown by SmirH.4 Spraying 
for peach leaf curl is regarded as of little value because the perennial mycelium 
of Exoascus deformans in the shoots produces a crop of diseased leaves each 
year in spite of spraying. As a matter of fact, there is no disease that can be 
controlled with more certainty and with more striking results by spraying 
than the peach leaf curl. Furthermore, the careful investigations of PreRCcES 
have shown that the origin of the spring infection is still obscure, but that 
probably the perennial mycelium in the branches has very little to do with 
the early infection. The common apple blotch fungus the author suggests 
3SmiTH, Ratpu E., Botrytis ane Sclerotinia; their relation to certain plant dis- 
eases and to each other. Bot, GAZETTE 29:369-407. pls. 3. figs. 3. 1900. 
4SmitH, ERwin F., Wilt disease of cotton, watermelon, and cowpea. U.S. Dept. 
Agric., Div. Veg. Physiol. and Path., Bull. 17. 1899. 
5Prerce, NEWTON B., Peach leaf curl; its nature and treatment. U.S. Dept. 
? 
Agric., Div. Veg. Physiol. and Path., Bull. 20. 1900. 
