TABLE OF CONTENTS: 
On the vegetation of tropical America, - : - - Lug. Warming : - 
The production of fluorescent pigment by bacteria, - - Ldwin O. Jordan 19 
‘On the life-history of Lemna minor (with figures I-59), - Otis W. Caldwell 37 
New or little known North American trees - - Charles Sprague Sargent 81 
The ecological relations of the vegetation on the sand dunes of Lake Michigan, 
Part 1. Geographical relations of the dune floras Abe figures I-26), 
Henry C. Cowles 95, 167, 281, 361 
The society for plant morphology and physiology —— Columbia meeting, 
W.F. Ganong 118 
Notes on the structure of the cenatiaa -sac in sigh om and Lysichiton (with 
Pp Dougias Houghton Campbell 153 
A pousbeetls of the genus Lilium (with figures 1-14), - - Ff. A.Waugh 235, 340 
Some appliances for the elementary study of plant physiology (with figures 1-7), 
W. F. Ganong 255 
Oogenesis in Pinus Laricio; with remarks on fertilization and embryology (with 
plates IV-VI), - - - - - - Charies J. Chamberlain 268 
Undescribed plants from Guatemala and other Central American Republics. XXI, 
: John Donnell Smith 331, 434 
Podophyllum peltatum (with figures 1-10), . . - : Theo. Holm 419 
New species of western plants, - - - - - T. S. Brandegee 444 
The effect of ether upon the germination of seeds and spores, C. O. Townsend 458 
BRIEFER ARTICLES — 
_ Additional host plants of Plasmopara Cubensis, — - - A. D. Selby . 67 
Copper in plants (with figure), —- = 4: =. WB, 7..MacDoygal 68 
Frost formations, - - - - - DT. MacDougal 69 
Another station for Thorea ramosissima, - “ Charles E.Bessey 71 
Notes on the maximum thermal death-point of Sporotrichum globuliferum, 
; Duggar 131 
Descriptions of two willows from Central America (with figures) 
W. W. Rowlee 136 
v [VOLUME XXVII 
