180 OTTO VERNON DARBISHIRE. 



LITERATURE. 



DARBISHIRE, O. V. : Beitrag zur Anatomie und Entwickelungsgeschichte 

 von Phyllophora : Bot. Centralblatt, Band 57, n. 12, 1894. 



DARBISHIRE, 0. V. : Die Phyllophora- Arten der westlichen Ostsee deut- 

 schen Antheils : Wissenschaft. Meeresunters. herausgegeb. v. d. Kom. 

 z. Unters. d. deutsch. Meere in Kiel, u. d. biolog. Anstalt. a. Helgo- 

 land. Neue Folge, Band 1, Kiel, 1895. 



G OMONT, M. : Note sur tin memoire recent de M. F. Schmitz intitule, ' Die 

 Gattung Actinococcus Ktz.' : Journal de Botaniqne, no. du l er Avril, 

 1894. 



KOLDERUP ROSENVINGE, L. : Deuxieme memoire sur les Algues marines 

 du Groenland : Meddelelser om Greenland, XX., Copenhague, 1898. 



Schmitz, Fr. : Die Gattung Actinococcus Kiitz. : Flora od. Allgem. Botan. 

 Ztg., Heft 5, 1893. 



EXPLANATION OF FIGURES IN PLATE XVII. 



Illustrating Dr. Darbishire's paper on Actinococcus and Phyllophora. 

 Actinococcus subcutancus (Lyngb. ) K. Rosenv. 



Fig. 1. Longitudinal section through the apical portion of a spermophore of 

 Phyllophora Brodiaei. The dark cells stained with iodine represent the cells 

 of the parasite, which has entered the host through the ostiole of the antheri- 

 dial cavity (at a). The parasite is branching in between the cells of the host. 

 A differentiation is already visible in the former into a root and shoot portion. 

 X250 diam. 



Fig. 2. General view of a longitudinal section through the apex of a spermo- 

 phore of Phyllophora Brodiaei, which has been successfully attacked by the 

 parasite, Actinococcus subcutancus. The intramatrical filaments, stained dark 

 blue with iodine, are clearly seen. From these arise the extramatrical fila- 

 ments, which have passed out of the tissue of the host, through the cortex. 

 They have formed a nemathecium, only part of which is seen in the drawing. 

 To the left of the section, at a, are seen four small antheridia-lined cavities. 

 XI 70 diam. 



Fig. 3. A single shoot-filament of the parasite breaking through the cortex 

 of the host. The outer covering of the latter is apparently undergoing some 

 change. X400 diam. 



Fig. 4. A bunch of shoot-filaments of the parasite forcing their way through 

 the cortex of the host. They are much branched. X400 diam. 



Fig. 5. A branching filament of the parasite forcing its way between the 

 medullary cells of the host-plant. The arrow points in the direction of the 

 cortex. X400 diam. 



Fig. 6. Section through the basal attachment of an older nemathecium, 

 showing clearly the boundary between the host and the parasite. X400 diam. 



