256 
Dr. Arthur Hollick exhibited a fruit of Ficus sp., from the Cre- 
taceous (Laramie) of Converse County, Wyo., sent for identifica- 
tion by Mr. Charles H. Sternberg 
This is the first specimen of a Ficus fruit reported from the 
Laramie formation, which is upper Cretaceous, and is an un- 
described species. A few have been found in the Dakota forma- 
tion, which is lower Cretaceous (F. neurocarpa Hollick, Bull. 
Torrey Club 30: 104. fig.B yr. 1903) and Mr. T. D. A. Cockerell 
has recently described one from the Tertiary shales of Florissant, 
Col. (F. Bruesi Cockrl.). 
These discoveries now give us the ancestral history of the genus 
from the lower Cretaceous through the Tertiary to modern times. 
Fossil leaves referred to the genus have been known from all 
these formations, but the identity of many of these was ques- 
tioned. The discovery of the fruits however show that the deter- 
mination of the genus from the leaves alone was correct. 
Mr. F. D. Kern spoke on the rusts of red and white clover. He 
showed that until recently the rusts affecting these two common 
economic plants have been considered as belonging to the same 
species, but that there are really two morphological species. The 
chief differences are in the urediniospores. Aside from the mor- 
phology there are also undoubtedly differences in the habit or 
life-histories of these species. The subject will be discussed by 
Mr. Kern in a paper soon to appear. 
Mr. Norman Taylor discussed temperature as a factor in local 
distribution of plants. In attempting to arrive at some conclu- 
sion as to the effect of temperature on the distribution of the 
plants growing within one hundred miles of New York, many 
interesting problems have arisen. The most obvious method of 
taking the annual mean temperature as a basis of calculation 
comes to nothing, as the differences in this are too slight to 
account for the very different vegetation in the Catskills where 
the mean temperature is 45°, and at Cape May, N. J., where the 
mean temperature is only 53°. The comparative similarity in 
the temperatures of the two places mentioned does not begin to 
express the great dissimilarity in the vegetation. 
Following the method used by some investigators of similar 
