464 
Johnson . — Two Irish Brown Algae. 
EXPLANATION OF FIGURES IN PLATE XXIV. 
Illustrating Prof. Johnson’s paper on two Irish Brown Algae. 
Fig. i. Tufts of L. Laminariae on the thallus of Alaria , nat. size. 
Fig. 2. A single large tuft. 
Fig* 3 * Cross-section of Alaria through bases of several tufts of L. Laminariae. 
x slightly. 
Fig. 4. Sterile cells of surface of sterile of filament. The large chromatophores 
are shown, x 320. 
Fig. 5. Surface of fertile part of filament showing unilocular u. s., and plurilo- 
cular sporangia p. s., mature and dehisced, x 320. 
Fig. 6. Longitudinal section of fertile part of the filament showing the sporangia 
and the large sterile medullary cells, m. x 320. 
Fig. 7. Transverse section of filament showing same as Fig. 6, and sterile surface 
cells (s. cl) ; b. a younger filament. x 320. 
Fig. 8. A single filament (plantlet), showing typical portions from base to 
apex: (1) is the base showing very few hairs and the detached connection; 
(2) shows the subarticulate appearance due to the large medullary cells and the 
hairs; (1) and (2) are sterile; (3) most of surface of fertile cells; (4) apex of 
filament, sporangia dehisced mostly, medullary cells bulging, x 70. 
Fig. 9. Anchorage of L. Laminariae (after Reinke), showing bases of three 
plantlets, Z, with rhizogenous filaments, r, and intra- cortical hyphae, h, in the 
thallus of Alaria , A. x 400. 
Fig. 10. Transverse section of L. pusillus showing unilocular sporangia, which 
are the only ones known, x 320. 
