Geology and Natural History. 75 
7. 
Characee ; . D. Hatstep.—The earliest paper directly re- 
lating to the American Chare appeared in this Journal in 1843, 
viz: the “Brief Notice of the Chare of North America, by Prof. 
Alex. Braun, communicated by Dr. Engelmann.” Two years 
later a notice of American Chare appeared in a note to Plante 
local lists and reports of different expeditions, until within the last 
ew years when the attention of our botanists has been more fre- 
quently turned to the species of this small but interesting order. 
The task of determining native species will be much facilitated by 
two works which have recently appeared. One by Dr. T. F. 
Allen entitled Characeee Americane, an illustrated work of which 
two parts have appeared, has already been noticed in this Journal. 
The other, originally presented as a graduating thesis at Harvard 
University in May, 1878, by Mr. B. D. Halsted, is now published 
in part in the Proceedings of the Boston Society of Natural His- 
tory. There is a short introduction, giving a general account of 
t t 
by Ravenel in the Santee Canal, and the beautiful C. gymnopus, 
a 
? 
s in Essex County, 
Robinson; and it is now known in other localities. As a whole 
the paper shows indications of careful study, and there is only one 
portion which we would criticize. The group of the Gymnopode 
including C. gymnopus and C. Robbinsii should be compared 
with C. polyphylla var. Michaueii Braun, which, as it seems to 
us, may have been confounded with what Mr. Halsted considers 
pe be the typical C. gymnopus. It should also be compared with 
C. sejuncta Braun, a species certainly approaching C. Robdbinsit. 
The literature of the old C. Michauwii and C. sejuncta is very 
obscure, and these two species figure unpleasantly in the foot- 
notes of inaccessible articles. But we hope to have eventually 
from Mr. Halsted a further elucidation of the Gymnopode. 
. @ F. 
8. Untersuchungen aber die Zellkerne der Thallophyten, by 
Prof. Fr. Scumrrz.—This paper, an extract from the Proceedings 
of the Niederrheinische Gesellschaft, is a general review of the 
mode of occurrence of the nucleus in the different groups of Thal- 
lophytes. In it the author has embodied his own observations, 
Which have been made principally in reference to Algw. He shows 
that the cells of certain genera which were supposed to be without 
® nucleus really have not one nucleus but a large number of 
nuclei, He considers that multinuclear cells occur tolerably 
