136 BOTANICAL GAZETTE [resem 
recognizes twenty-two species, of which two are imperfectly known, Tk 
drawings, illustrating the species, made by the author, are admirable inthe 
clearness and fullness. The following changes from the names in Gms 
Manual are noted: #. Pennsylvanica has already been transferred to Jubult 
f, saxicola is referred to F. Virginica, and F. fragilifolia Aust. (not Tayi) 
F. Selwyniana Pearson; F. @olotis is F. riparia VJ ampe; and F, dilatatas 
described as /. Brittonie, n. sp. a 
Mr. Marshall A. Howe has lately examined the species of Porth’ 
belonging to North America. Schiffner in Englerand Prantl’s Pflanzenfamilia 
rejected the name Madotheca, which Dumortier adopted for this genus,al 
also considered Porella a nomen nudum of Linnzeus. But Howe, backeily 
the recent examination by Underwood of the Dillenian plant at Oxford, fo 
lows Lindberg and others in the use of Porella. He recognizes eight species 
The five of Gray’s Manual are pretty well changed. P. Sud/ivantit is refer@ 
to P. pinnata; P. Thuja to P. platyphylla, while P. dentata become! 
rivudaris (Nees) Trevis.—C. R. B. 
AFTER LONG interruption the Contributions fron the Botanical Labora 
of the University of Pennsylvania have been resumed by the publication & 
no. 3 of vol. I. It contains three papers: A chemico-physiological study 
Spirogyra nitida, by Mary E. Pennington, Ph.D.; On the structure and pt 
lination of the flowers of Eupatorium ageratoides and E£. covlestinum, 
Laura B. Cross, Ph.D.; and Contributions to the life-history of Amphica 
monotca, by Adeline F. Schively, Ph.D. The first of these papers '§ P : 
larly meritorious. Not only does it bring out some interesting pis 
which are connected with those already known, but it shows ingenuity 
devising and execution of the experiments. Particularly useful to 
workers will be the carefully described set of color screens, by _ 
which monochromatic light may be secured. They seem a decid : 
ment on other formule. Perhaps the most interesting conclusion - 
influence of monochromatic light on the growth of Spirogyra is due® 
to the effect of the particular light on diastase. 
The second paper is very brief. By her experiments 
to the conclusion that self-pollination in the two species of = a 
very rare indeed, and that even when it does occur the fruits a 
germinating Capacity. The visits of insects, however, insure 4° 
centage of good fruits. - 
The third paper is a very detailed account of the morph aa 
ology of Amphicarpaa; a useful catalogue of facts, but not com 
others by the author. One fact of interest is that this plant ee 
circumnutation movements, completing a circuit in 51 minutes ~~ : 
* Howe, MaRsHALL A.—The North American species of Porella. * 
the Torrey Botanical Club 24:512-527. N 1897. 
