Cell Structure, Growth and Division in the Antheridia 
of Polytrichum Juniperinum Willd. 
By 
Charles E. Allen. 
With Plates VI — IX. 
Contents. 
Page 
Introduction 121 
Terminology 128 
Material and Mlthods 130 
Observations 131 
The Structure and Division of the Androgones. 131 
The Cytoplasmic Structures and Spindle Formation 131 
Karyokinesis 138 
Cytokinesis 144 
The Androcyte Mother Cells 147 
The Cytoplasmic Structures and Spindle Formation 147 
Karyokinesis 156 
Cytokinesis 158 
Discussion 159 
The Organization of the Cells 159 
The Kinetos omes 163 
The Blepharoplast 169 
Peculiarities of Mitosis in the Bryophytes. . . . 177 
Literature Cited 179 
Description of Figures 186 
Introduction. 
Since the results of the present study, although it has been confined 
to the antheridial cells, throw some light upon certain problems of cell 
Organization and behavior whieh are common at least to all the musci, 
it seems worth while at this point to refer to such observations as have 
