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111. STUDIES IN THE GENUS PHYSCOMITRIUM. By Elizabeth 
G. Britton. 
Physcomitrium is a genus of small mosses, growing on the 
ground and maturing the sporophyte in early spring. The 
species are remarkable for the great diversity in form of the 
sporocarp before and after dehiscence. Eleven North Ameri- 
can species are now known, four of which are new to science. 
Exhibits: Microscopic preparations of some of the species, 
showing structure of the vegetative and reproductive or- 
gans. 
M2.) SEUDIES, IN THE GENUS POLYSIPHONIA. By Carlton C. 
Curtis, Ph.D: 
Polysiphonia is a genus of the Red Alge (Floridez), consist- 
ing of a large number of species of wide distribution in all 
oceans. The present study is an investigation of the anatomy 
and systematic relationships of those occurring on the coasts 
of North America. 
Exhibits (a.): A selection of the species, mounted as her- 
barium specimens with drawings. (¢.) Microscopic prepar- 
ations showing: 1. Cross-section of the thallus. 2. Tetras- 
pores (propagative organs). 3. Antherids and cystocarps 
(reproductive organs). 
113. EARLY STAGES IN THE DEVELOPMENT OF THE LICHEN 
MHALLUS.. By Carlton C Custis, Ph. DD. 
A lichen is a composite plant, consisting of a fungus in sym- 
biotic relationship with one of the simpler algz, on which it 
is parasitic. The earliest stage of this symbiosis has recently 
been observed in nature. 
Exhibits : Microscopic preparations showing: 1. The alge be- 
coming infested by the fungus. 2. Section through completed 
thallus. 3. Specimens of foliaceous, crustaceous and fruticose 
lichens. 
114. STUDY OF CORK-WINGED STEMS. By Emily L. Gregory, 
eh: 
A study of certain curious cork formations, which seem eccen- 
tricities rather than normal developments. 
