124 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



Fig. 5. Vegetative cells, with trichophoric cell and part 

 of trichogyne. X 450. 



Fig. 6. Mature carpospores in the cortex of a cystocarpic 

 ramulus, two trichophoric systems nearer the 

 periphery. X 350. 



Fig. 7. Very young stage in the development of a cysto- 

 carpic ramulus. X 350. 



Fig. 8. Young stage in the development of an ordinary 

 vegetative frond. X 350. 



Plate III. 



(Reprinted by permission from the Journal of the Linncmn Society, Botany.) 



Figs. 1 — 5. Bhodochorton seiriolaniim ', figs. 6 — 11, B. 

 rothii ; fig. 12, B. Jiorididitm. 



Fig. 1. Part of a branch of Polijsiphonia urceolata with 

 B. seiriolaniim epiphytic upon it. X 55. 



Fig. 2. The same, shewing terminal and secund sporangia. 

 X 350. 



Fig. 3. The basal layer from which the upright filaments 

 arise. X 350. 



Fig. 4. Innovation of a vegetative filament after the 

 escape of the tetraspores from a terminal spor- 

 angium. X 450. 



Fig. 5. Terminal sporangium with tetraspores, and in- 

 novation of a subterminal sporangium. X 450. 



Figs. 6, 7, 10. Various stages in the development of 

 sporangia formed by innovation. X 450. 



Figs. 8, 9. Innovation in vegetative filaments. X 350. 



Fig. 11. Development of sporangia from buds of subapical 

 cells ; in one case the spores have escaped and a 

 second bud is developing in the cavity of the 

 empty sporangium. X 350. 



