200 Phillips. — The Development of the Cystoccirp 
EXPLANATION OF FIGURES IN PLATES 
XV AND XVI. 
Illustrating Prof. Phillips’ paper on the Development of the 
Cystocarp in Rhodymeniales. 
The figures are to be regarded as of a semi-diagrammatic character. They were 
sketched for the most part by means of the camera lucida, but cells lying at 
different levels have often been figured together, and cells are sometimes left out 
for the sake of clearness. The cells hatched by means of oblique lines are in all 
cases those of the carpogonial branch, those hatched by means of horizontal lines 
in Figs. 20 and 25 are the central cell and its adjacent readily stained cells. 
The cells with red outlines are those of the sterile filaments derived from the 
pericentral cell of a fertilized procarp. In Figs. 21, 27, 28, 30, 31, and 32, the 
red colour is also employed for these cells, although the procarps are not yet 
fertilized. The auxiliary cell and its derivatives are shown with somewhat 
thickened outlines. In the figures disposed horizontally, the same orientation of 
parts is preserved throughout, that is to say, the anterior part of the thallus is to 
the right. 
Abbreviations : aux. c., auxiliary cell ; c. c., central cell ; carp ., carpogonium ; 
carp.br ., carpogonial branch; cpst . , carpostome ; gonbl gonimoblast-filament ; 
in. st. br ., inferior sterile branch ; /. st. br., lateral sterile branch ; peric. c., peri- 
central cell ; tr., trichogyne. 
PLATE XV. Figs. 1-16. 
Delesseria sanguinea , Lamx. 
Fig. 1. An old midrib, giving rise to three sterile branches, and numerous 
cystocarp-bearing branches in various stages of development. Natural size. 
Figs. 2, 3, 4. Views of the flat surface of a thallus- segment upon which a 
cystocarp is developing, x 15. 
Figs. 5 and 7. Lateral or profile views of two stages in the development of 
a cystocarp upon such a thallus-segment. X 15. 
Fig. 8. Front view of a procarp-bearing branch, showing the row of axial cells, 
the pericentral cells derived from them, and the carpogonial branches turned 
alternately to the right and left, x 75. 
Fig. 9. Lateral view of a procarp-bearing branch at the same stage. The axial 
cells are shown, and the paired pericentral cells of the upper and lower surface, 
each bearing a carpogonial branch emerging at the corresponding surface, x 75. 
Fig. 10. Mature cystocarp-bearing segment, showing the apical flap remaining, 
and the lobing of the contents of the cystocarp. x 10. 
Fig. 11. Magnified view of a segment at the same stage, and of the same view 
as in Fig. 8. The eighth segment behind the apical cell has an immature procarp, 
afterwards the carpogonial branches are fully developed, x 600. 
