826 The American Naturalist. [September, 
S. M. Tracy, Distribution of the Gramines in the United States. 
Illustrated by many maps. 
. L. BRITTON, A consideration of species based upon the theory of 
evolution. An attempt to formulate our present ideas of species. 
ErmansETH G. Brirron, A revision of the genus Physcomitrium. 
Showing that while we supposed that we had half a dozen species, it 
appears that we have nearly or quite double that number. 
W. T. SWINGLE, On Cephaluros mycoidea and Phyllosiphon sp., two 
parasitic algæ new to North America. These curious plants, the first 
of which lives upon Magnolia leaves and the latter upon the leaves of 
Arisema, appear to be truly parasitic. 
FREDERICK V. CoviLLE, An analysis of the conditions affecting the 
distribution of plants. These were given as temperature, light, food, 
water and mechanique. 
J.C. ARTHUR, Deviation in development due to the use of unripe 
seeds. As this paper will be published in full in the NATURALIST, no 
summary will now be attempted. 
W. T. SwisGLE, The principal diseases of citrous fruits now being 
studied at Eustis, Fla. Illustrated by specimens of fresh material. 
P. H. Rorrs, A sclerotium disease of plants. Giving details of the 
Structure. 
ELIZABETH G. Brirron, Ulota americana Mitten and Orthotrichum 
americanum Beauv. The author discussed fully the question of their 
identity, which appears to be established. 
The following were read by title for want of time: 
L. H. PawMEL, Notes on Restelia pyrata, Crossing of Cucurbits 
and A case of poisoning by the wild parsnip, Cicuta maculata, (three 
papers). 
The Botanical Club held sessions on Friday, Monday and Tuesday. 
It received the report of the committee appointed last year to prepare 
a check list of North American phanerogams, and after much dicus- 
sion, provision was made for printing it. In this connection, Rule III 
of the “ Rochester Code," was modified so as to allow the use of a 
specific name identical with the generic. The rule now reads as fol- 
lows: 
“In the transfer of a species to a genus other than the one under 
which it was first published the original specific name is to be 
retained." 
Another important action of the club was that relating to the pro- 
American botanical society. A committee of ten was elected 
and empowered to increase its number to twenty-five, to organize such 
a society. The following is the committee: J. C. Arthur, G. F. 
