The Reproduction and early Development of Laminaria 
digitata and Laminaria saccharina. 
BY 
G. HAROLD DREW, B.A. 
Late Scholar oj Christ's College , Cambridge , and University Scholar of St. Mary's Hospital. 
With Plates XIV and XV. 
Table of Contents. 
PAGE 
Introduction. 
Summary of the more important Characters of the Plants . . . i^S 
Methods.^ 
Collection of specimens. 179 
Preservation of living specimens . . . . . . . . . • 179 
Examination of the reproductive areas . . . 180 
Culture methods . . . . . . . . . . . , .181 
The Reproductive Process.183 
Development of the Young Plant.^6 
Summary of Results.188 
Bibliography.189 
Description of Plates.. 
Introduction. 
T HE possibility of obtaining the early stages of the life-history of some 
of the Laminariaceae, and of following their growth in artificial 
culture solutions, was suggested to me by some experiments undertaken by 
Dr. E. J. Allen and Mr. E. W. Nelson, in the winter of 1907-8, to determine 
the conditions of growth of the Diatomaceae. In some of these experi¬ 
ments young specimens of Laminaria digitata were noticed growing in 
culture solutions which had been inoculated with Plankton. 
The present work was undertaken in the winter of 1908-9. I have 
to thank the Council of the Marine Biological Association for placing at my 
disposal a table at their Plymouth Laboratory. I have especially to thank 
Dr. Allen and Mr. Nelson for their kind assistance and advice. 
No account of the reproductive processes in the Laminariaceae has 
been published. A good description of the structure of the reproductive 
areas is given in Oltmanns’ ‘ Morphologie und Biologie der Algen 5 and 
[Annals of Botany, Vol. XXIV. No. XCIIL January, 1910. ] 
N 
