Johnson. — On Stenogramme interrupta. 367 
EXPLANATION OF FIGURES IN PLATE XXIII. 
Illustrating Professor Johnson’s paper on Stenogramme interrupta. 
Fig. 1. A portion of a tetrasporic plant, slightly magnified : s sorus, s', empty 
one. 
Fig. 2. Three tetrasporangia : ts shows the tetraspores cruciately arranged, 
x 350. 
Fig. 3. Cross-section through two young sori, on opposite sides of the thallus. 
x 350. 
Fig. 4. Male plant, natural size : a , antheridium. 
Fig. 5. Portion of antheridium in surface view, showing mother- cells of sper- 
matia. x 400. 
Fig. 6. Vertical section through two antheridia. x 200. 
Fig. 7. Portion of sterile surface of thallus : contents of the superficial cells not 
shown, x 400. 
Fig. 8. Portion of female plant showing fertile lines,/!/. The dark spots in 
the lines indicate young cystocarps. x 1 o. 
Fig. 9. Figure to show relative thickness of ripe fertile line : t, thallus, /, the 
wavy fruit- wall. 
Fig. 10. Cross-section through the fertile line fl. Five or six procarpia are 
indicated. x 80. 
Fig. 11. Procarpium just after fertilisation : t, trichogyne with remains of sper- 
matium, cut off from c, the fertilised carpogonium-cell now fused with m. c., the 
medullary mother-cell of the carpogenous branch of which the two cells c c" later 
disappear ; t. c. ordinary thallus-cells ; 0, surface of thallus. x 500. 
Fig. 12. a, b,c various young central cells of cystocarps: m.f. meta-ooblastema 
filaments. X350. 
Fig. 13. Vertical section of fertile line to show the rich medullary cells m' . c. at 
the time of fertilisation of the procarpia. x 80. 
Fig. 14. A single medullary cell of Fig. 13. x 300. The peg-like projections 
represent points of connection with adjacent cells. 
Fig. 15. Carpospores. x 500. 
Fig. 16. Vertical section of ripe fertile line. The central granular-looking mass 
represents many cystocarps from which carpospores have become free here and 
there : f. w. fruit- wall, x 50. 
