. 824 Scientific Mpteingencs. 
9. Beitrdge zur Morphologie und Physiologie dev Pilze, Vierte 
Rethe ; by A. DeBary and M. Woronin.—After an interval of 
sae far from ten years, the important series of papers by DeBar 
and Worouin, published under the above title in the Abhandl. 
iadikiak. Gesellsch., is continued in a fourth part which contains 
. paper by DeBary on Investigations on the Peronosporew and 
Saprolegniew and the Abiosstgee of a Natural System of Fungi. 
The article covers 137 quarto pages, with six lithographic plates. 
The subject is treated ees sixteen different heads, of which the 
first twelve are devoted to an account of different forms o Py- 
thium, Pelcsonners he, Peronospora, Saprolegnia, Achlya and 
myces. With the exception of some hitherto undescribed 
nabiae, “the writer has confined himself principally to the changes 
which oceur in the formation of the oogonia and antheridia, giving 
with great minuteness the details of the process of fer tilization, 
In the genera like Pythium and Peronospora where only one 
oospore is produced in an oogonium, the oospore is separated from 
the oogonium wall by a layer of protoplasm to which DeBary 
gives the name of periplasma, and he thinks that the markings 
formed on the outer coat of certain oospores is formed directly 
from the periplasma, and is not an exudation from the cellulose 
wall of the spore itself. In Pythium a small process, or befruch- 
tungsslauch, bibdersiel the oogonium wall, ane reaches the 
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and the matter w hich escapes pa ae, pethoridial pr sete consists 
of only a few granules and the whole axial portion does not escape 
asin Pythium. : 
In Saprolegnia and Achlya nothing could be seen to be dis- 
charged from the antheridial tubes and the fertilization consists 
mer rely i in the _— of the male ee with the surface a the 
oospores. Contrary to the view advanced by Pringsheim, DeBary 
finds that os thin spots in the: oogonium walls of some species, 
be distinct species rather than accidental variations of species in 
which antheridia normally occur. He does not deny that forms 
