224 BOTANICAL GAZETTE | SEPTEMBER 
E. L. Mosety: A comparison of the flora of Erie county, Ohio, 
with that of Erie county, N. Y.—Both districts are adjacent to 
Lake Erie, but the Ohio district (including Erie county and the 
peninsula and islands of Ottawa county) contains 265 native 
species of phanerogams not known to occur within fifty miles of 
Buffalo. The cause is mainly climatic. The average date of 
the last killing frost in spring at Sandusky is April 30, at Buffalo 
it is May 20; the first killing frost in autumn at Buffalo is Sep- 
tember 15; at Sandusky it is October 24; and the summer is 
decidedly cooler at Buffalo. Reasons for the difference in cli- 
mate were given, including the blowing of the ice to the east 
end of the lake in spring and other considerations. 
Cuartes E. Bessey: The significance of the compound ovary.— 
In the study of the gyncecium of angiosperms we are forced to 
conclude that its primitive condition was apocarpous ; in other 
words, that whether monocarpic or polycarpic there was at least 
no union of ovary with ovary. The original ovary was doubtless 
simple. Bya comparative study of the ovaries of existing plants 
we are led to the conclusion that the syncarpous gynoecium was 
derived from the apocarpous gyncecium. This is so plain that tt 
is needless to dwell upon it. Both phylogenesis and ontogene- 
sis furnish us with numerous illustrations of the truth of this 
statement. 
It is to be observed that the compound ovary is a compata- 
tively stable structure, and that it changes slowly within any 
natural group, or in passing from group to group. No part ob 
plant is more stable, yet with all its stability it undergoes changes 
in certain directions. It is a common occurrence to find ee 
tacarpellary ovary reduced to four, three, or two carpels, and o 
may proceed until, as in some of the Caryophyllacee, we seem to 
have but one carpel remaining. In rare cases there appeats sg 
be a reversion from Syncarpy towards apocarpy, as in the Apo- 
cynacee and Asclepiadacez, but as a rule it may be said that 
syncarpy once attained by a group is persistently maintained, 
however much of simplification it may otherwise have undergone. 
