b4 
plants in order to make space for the experimental culture of 
few types. This means that from time to time, some of the vari- 
eties represented only by a single plant are accidentally lost, and 
disappear from the collection. In the summer an extension of 
space has been possible through the use of a lath-shaded area in 
the experimntal ground out-of-doors, and through the tempo- 
rary use of space in the children’s greenhouses. As a by-product of 
the experimental cultures, there were again more than a thousand 
plants on which observations had been completed, which were 
turned over to the Department of Elementary Instruction, 
Cooperation with Florists —A continuation of visits and corre- 
spondence with florists interested in the culture of ferns together 
with some distribution of sets of varieties for experimental pur- 
poses, and of articles in florists’ trade press, have constituted the 
cooperative work for 1923. 
Ecology 
Research on the Forests of Long Island was continued during 
the year, especially with reference to the occurrence of the Pitch 
Pine (Pinus rigida) on Long Island and on Mt. Desert Island, 
Maine. Weekly readings of instruments measuring evaporation, 
and soil temperatures at different depths, were secured both here 
and in Maine, the latter in cooperation with Major Barrington 
Moore. The results of this work on the vegetation of Mount 
Desert Island are now in course of writing. 
Studies of the salt-marsh vegetation on Long Island, begun with 
the thought of the ultimate agricultural utilization of these tracts, 
were carried on, and are described in greater detail in the ap- 
pended report of the Curator of Plants. 
The fact that the curator has been obliged to meet a portion of 
the cost of this field work from his personal funds serves to 
emphasize how woefully inadequate our resources for scientific 
work are in comparison to our needs. 
Plant Classification 
Studies of floral structures from an evolutionary point of view 
have been continued by Dr. Gundersen. The old divisions of 
dicotyledons, based upon absence, presence, or union of petals, 
