VOLUME XLII NUMBER 6 
DOTANICAL. Greaeel ee 
DECEMBER 1906 
THE LIFE HISTORY OF POLYSIPHONIA VIOLACEA. 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY. 
LXXXVI. 
SHIGEO YAMANOUCHI. 
(WITH THREE DIAGRAMS AND PLATES XIX—XXVIII) 
INTRODUCTION. 
THERE have been published by various authors many accounts 
of investigations on the red algae treating of the morphology of the 
thallus, the development of the cystocarp, and tetraspore formation. 
The first general studies on the reproductive processes in the group 
were those of BoRNET and THURET (12) and JANCZEWSKI (43). These 
papers have never been surpassed in clearness of expression and 
beauty of illustration, but they considered simply the outer mor- 
phology or histology and gave no cytological details of fertilization, 
nor did they trace the life history. ScHmitz (69) published an 
account of the fructifications of more than forty species in various 
groups of the red algae, giving special attention to the auxiliary 
cells, but in his conclusions he failed to distinguish between the act 
of fertilization and the secondary fusions concerned with the auxiliary 
cells, and he developed elaborate speculations in which these fusions 
Were included as a part of the sexual process. This misconception 
was cleared up by OrtmManns’ discovery (55) that the real sexual act 
is the union of male and female gamete nuclei in the carpogonium, 
and that the auxiliary cells are probably only concerned with the 
nourishment of the cystocarp. OLTMANNS. was the first author to 
develop the theory that the structure derived from the fertilized carpo- 
gonium was sporophytic in character; however, he presented no 
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