S lurch. — Harvey el la mirabilis ( Schmitz & Reinke). ioi 
EXPLANATION OF FIGURES IN PLATES 
III AND IV. 
Illustrating Mr. Sturch’s paper on Harveyella. 
The figures are to be regarded as of a semi-diagrammatic character. They 
were sketched by means of the camera lucida, but cells lying at different levels 
have often been figured together. All the figures have been slightly reduced in 
reproduction. 
Abbreviations: aux. c., auxiliary cell ; carp., carpogonium ; carp, br., carpo- 
gonial branch; gonbl., gonimoblast-filament ; per. c., peripheral cell; si. br., 
sterile branch. 
Fig. i. Longitudinal section of a Rhodomela- stem, with filaments of a young 
Harveyella mirabilis growing among the Rhodomela- cells. In Figs, i and 2 the 
cells of the Harveyella are dotted. Zeiss apochromat 16 mm., Oc. 8. 
Fig. 2. Longitudinal section of a swollen Rhodome la-stem, with somewhat older 
Harveyella mirabilis . Zeiss apoc. 16 mm., Oc. 8. 
Fig. 3. Longitudinal section of a Rhodomela- stem, with a mature cystocarpic 
H. mirabilis. The cells of the host-plant which contain food-material are dotted ; 
the food-material has been exhausted in those cells of the host which are left 
blank. The cells of the gonimoblast-filaments of the Harveyella are black. 
Zeiss apoc. 16 mm., Oc. 8. 
Fig. 4. A portion of a branch of Rhodomela subfusca with Harveyella mirabilis 
growing on it. x 3. 
Fig. 5. Peripheral filaments bearing antheridia. Zeiss apoc. 8 mm., Oc. 18. 
Fig. 6. Peripheral filaments bearing tetraspores. Zeiss apoc. 8 mm., Oc. 18. 
Fig. 7. Portion of a section of a tetraspore-bearing frond. Zeiss apoc. 16 mm., 
Oc. 8. 
Figs. 8 and 9. Stages in the development of the procarp. Zeiss apoc. 8 mm., 
Oc. 18 : reduced |. 
Fig. 10. Procarp and auxiliary cell after the development of the two sterile 
branches. Zeiss apoc. 8 mm., Oc. 18 : reduced j. 
The cells of the sterile branches have thickened outlines in Figs. 10, 11, and 12. 
Fig. 11. Mature procarp ready for fertilization. The thallus-cell beneath the 
auxiliary cell has cut off a small cell from its basal part. Zeiss apoc., 8 mm., 
Oc. 18 : reduced \. 
Fig. 12. Procarp with fertilized carpogonium, which has not yet copulated with 
the auxiliary cell. Zeiss apoc. 8 mm., Oc. 18 : reduced \. 
Fig. 13. Fusion of carpogonium and auxiliary cell. The upper part of the 
carpogonium and the trichogyne were cut off in sectioning. Zeiss apoc. 8 mm., 
Oc. 18 : reduced \. 
