1915] CURRENT LITERATURE 163 
or fifty years, commencing with KERNER, many European botanists 
eas called attention to the relatively xerophytic features of limestone plants. 
Hossevus? shows that these same features hold for the tropics. His studies 
were made on a mountain in northern Siam, and he records the cote: 
xerophytic habits as characteristic: shortened, lignified, much-branched 
reduced leaf surfaces; involute leaves; succulence, etc.—H. C. Mies 
The chestnut disease.—ANDERSON and RANKIN” have published a bulle- 
perents the known facts in a bd convenient site: t seems that this 
‘canker” was first discovered by MERKEL in 1904 on the American chestnut 
] 
to Virginia; and has spread westward into New York and Pennsylvania, but 
has not yet been found in Ohio or Indiana. 
The name of the causal organism has been under considerable discussion, 
and the various views are presented. The authors adopt Endothia parasitica 
ae Anders. The morphology i is speiiaan: in detail, Anes of stromata, 
cnidia, pycnospores, perithecia, ascospores, and my 
on that the American chestnut (Cacao dentata) is by ae the most sus- 
ceptible host, but no species of Castanea has been proved to be immune, 
though some of the oriental varieties show a certain amount of resistance. 
The conclusion at present is that this disease is not a serious menace to any 
forest tree except the chestnut. The problem of dissemination is discussed 
in detail, including such factors as man, insects, rain, birds, wind, and other 
minor agencies, 
Naturally the subject of control is discussed with all available data, and 
the general conclusion is reached that ‘“‘at present we know of nothing that 
will prevent the extermination of the American chestnut tree.’’ The authors, 
however, “do not believe that the ingenuity of our scientists 2 been ex- 
hausted,” a hopeful belief which we trust will be justified—J. M 
Morphology of Peperomia hispidula.—JoHNsoN™ has made a detailed 
study of this species, having a very simple vegetative structure and a peculiar 
* Hosseus, C. C., Edaphische Wirkungen des Kalkes or - Vegetation tro- 
pischer Karren und Racetatelder Bot. Jahrb. 45:661-669. 1 
ANDERSON, P. J., and , W. H., Endothia canker an eeatoak Cornell 
Univ. Agric. Exp, Station Bull. 347: 533-618. pl. 37. figs. 10. 1914. 
Ponies Duncan S., Studies of the development of the Piperaceae. II. 
an need-developuient of Peperomia hispidula. Amer. Jour. Bot. 1: 
ay 357-397. pls. 36-38, 41-43. 1914. 
