TABLE OF CONTENTS. 
On the endosperm and embryo of Peferonia pellucida (with plate 1) Sue 
Duncan S. Johnson I 
New or unrecorded mosses of North America. I. (with plates 11-v) 
J. Cardot and 1. Thériot 12 
The Ye of the oo sac in some meapantage daar plants (with 
$s VIand VII) - - Karl M. Wiegand = 25 
The developmen and function of the cell pn in pais plants (with plates V1II 
H. G. Timberlake 73,154 
Contributions from the Cryptogamic Laboratory of Harvard University. XLIV. 
New or little known unicellular eae bag hope Cohnii (with 
George Thomas Moore 100 
Origin of the cones of the multipolar spindle in Gladiolus ith plate x1I} 
vuther A. Lawson 145 
Physiological observations on some perennial herbs (with sisi XIII) 
A. Rimbach 171 
Contributions from the Rocky Mountain Herbarium. I - - Aven Nelson 189 
Cell and nuclear division in Fudigo varians (with plate xiv) - &.A. Harper 217 
Double fertilization in Compositae. pail S6ite from the Hull Botanical 
Laboratory. XXI (with ree XV and XV W.J.G. Land 252 
A new chromogenic micrococcus (with four aa - - Mary Hefferan 261 
On the nature of the stimulus which causes the change of form in polymorphic 
green alge. Contributions from the Hull Botanical Laboratory. XXII 
(with plates XVII and XVIII) - Burton Edward Livingston 289 
Observations on Lessonia (with — doy - - Conway MacMillan 318 
Studies in Crataegus. II - - - - 3: (CD pedald © 335. 
The achromatic spindle in the spore mother cells of Osmunda regalis. Contri- 
butions from the Hull Botanical Laboratory. - XXII (with plate xxi) 
R. Wilson Smith 361 
Studies on chromogenic bacteria. I. Notes on the pigment of Bacillus poly- 
chromogenes (with sixteen figures)  - E. M. Chamot and G. Thiry 378 
Notes on the division of the cell and nucleus in liverworts (with plate XXII!) 
; an Hook 394 
BRIEFER ARTICLES — 
Some observations on apple tree anthracnose (with twelve figures) 
A. B. Cordiey 48 
VOLUME Xxx] v 
