104 
in leaves with no bloom on either surface there is a decided ten- 
dency towards the accumulation of stomata in the lower epidermis; 
in leaves with bloom on the lower surface only, which is thus 
protected from wetting, the tendency is even stronger in the same 
direction ; in those which have bloom only on the upper surface, 
there appears to be an accumulation of stomata on this surface, 
but the few species examined render this somewhat untrustworthy 
as a general conclusion ; leaves having bloom on both surfaces, 
sometimes have more stomata above than below, and sometimes 
the reverse is the case. 
Proceedings of the Club, 
The regular monthly meeting was held at Columbia College 
Tuesday evening, May 11. Dr. Newberry presided, and twenty- 
six persons were present. Miss Louise M. Stabler was elected 
active member and Miss Mary C. Cook corresponding member. 
Mr. E. E. Sterns distributed the title-page and prospectus of a 
catalogue of the plants of Manhattan Island, requesting the aid 
of the members in making it as complete as possible. Professor 
Schrenk exhibited a pod from a cleistogamous flower of Viola 
cucullata, in which sixty-six seeds had sprouted and the seed- 
lings had attained the height of nearly two inches; when he 
pulled it up they still remained attached to the pod. He also 
read a list of thirty-three wild plants in his garden, among them 
Dodecatheon Meadia and Isopyrum biternatum. Professor Day 
read a list of additions to the Flora of Westchester County. Mr. 
Poggenburg read a list of fifty-seven plants collected on the 
23d and 24th of April, and Mrs. Britton reported Nuphar 
advea in bloom on the 25th. She also exhibited an acorn of 
the white oak with four cotyledons and two radicles. Dr. Brit- 
ton exhibited a series of specimens of Populus grandidentata and 
P. heterophylla, and read some notes on the differences in the 
leaves and nomenclature. Mr. P. H. Dudley read the paper 
announced for the evening on the formation of ducts in the 
chestnut, Castanea vulgaris, var. Americana DC., comparing 
_ them by means of wood sections and photo-micrographs with 
those of the Hemlock, 7suga Canadensis, Carr., and the Larch, 
Larix Americana, Michx. 
