TABLE OF CONTENTS 
The life history of Zanardinia. Contributions 
from the Hull Botanical Laboratory 174 we 
twenty-four figures and plates I-IV) - Shigéo Yamanouchi 
The origin of the erect cells in the phloem of the 
Abietineae (with twelve figures)  - M.A. Chrysler 
Undescribed plants from Guatemala and mike 
Central American Republics. XXXVII - John Donnell Smith 
Contributions from the Be Mountain Her- 
barium. XIII - Aven Nelson 
Seed production in Yucca uc - - Max M. Ellis 
The origin and development of the point sac and 
embryo of Dendrophthora opuntioides and D. 
gracile, I ib six ae and a V and 
VI) - - Harlan Harvey York 
The icing of the slier of T; veil pratense. — 
Contributions from the Hull Botanical Labora- 
tory 175 (with one figure) - - J. N. Martin 
Observations on the gia tg of the aroids vith 
forty-seven figures) - James Ellis Gow 
Summer evaporation intensity as a Picritaing 
factor in the geneeese of vegetation in 
Connecticut - os George Elwood Nichols 
Semipermeability of oe coats. Contributions 
from the Hull Botanical — I 
(with nine figures) ee Charles A. Shull 
The origin and devalopehent ¢ of the embryo sacand 
: embryo of Dendrophthora eat at and D. 
- gracile. II (with plate VII) - - - Harlan Harvey York 
Xenia and the endosperm of angiosperms = - E. M. East 
“~Can fungi living in agricultural soil assimilate free 
nitrogen ? (with eighteen figures) - H. N. Goddard 
Phryma leptostachya L., a —_- study : 
(with plates VIII-X) - Theo. Holm 
Nuclear division in Spirogyra crassa vc me 
XI and XII) - M. L. Merriman 
Filices Purdomianae - - - - - - Cari Christensen 
Vv 
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