68 BOTANICAL GAZETTE [JANUARY 
Benincasa cerifera or Cyclanthera explodens. This Plasmopara has | 
previously been reported upon five of the above named hosts, and upon | 
Cucumis Anguria and Cucumis moschata ;* its appearance upon so large 
a number of new hosts has added interest to this part of the study. In 
every case the cucumbers and muskmelons were first attacked, then the 
other cucurbits. No plant outside the order has as yet been attacked 
by this Plasmopara and no oospores have been discovered here either 
for Plasmopara Cubensis or Plasmopara australis (Speg.), which was 
found in abundance on Sicyos angudatus and sparingly upon adjoining 
plants of AZicrampelis lobata adjacent to a diseased pickle field. It may 
be further observed, that Plasmopara Cubensis (B. & C.) is clearly dis- 
tinct from Plasmopara australis (Speg.) whether examined upon the | 
Py 
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same hosts (Micrampelis and Sicyos) or upon the different hosts of 
the former. 
I shall be pleased to supply, as far as possible, to any mycologists 
who may desire them, specimens of these fungi upon the various 
hosts.—A. D. SELBy, Ohio Agricultural Experiment Station, Wooster, — 
Ohio. - ee 
COPPER IN PLANTS. 
Copper is an element of very wide distribution in the bodies of 
plants, a matter which appears to be determined by the presence of 
the metal in the soil rather than by the exercise of any selective power 
Specimens grown in ordinary soils may contain as much as 30° © 
this substance to each kilogram of dry matter, while those in rich soils Z 
may yield 560" from the same quantity of dry matter according t0 
Lehman? The wood of a tree, Quercus macrocarpa Michx., recently 
submitted to Professor Frankforter of this university for chemical anal: 
ysis, was found to contain slightly less than s00™ of copper to each kilo 
of dry matter. When the matter was called to the attention of th 
writer, the entire trunk and crown of the tree had been carried aways 
with the exception of a short stump from which the bark had been 
stripped. This rendered impossible any attempt to determine t 
distribution of the substance throughout the plant. It was evide 
however, that it was dead before it had been cut down. The examina 
of the material at hand showed the copper in the form of finely divi 
* Stewart, Bull. N. Y. Expt. Station. 
. Der Kupfergehalt von Pflanzen und Thieren in kupferreichen Gegenden- 
fur Hygiene 27:1. 1896. 
Ar 
