120 Cavers . — The Structure and Biology of Fegatella Conica. 
Fig. 28. Antheridial receptacle, seen from above ; v. s. ventral scales, x 10. 
Fig. 29. Part of horizontal section through antheridial receptacle : v. s. ventral scales. Two 
antheridia are shown occupying a single cavity, in lower part of figure, x 200. 
Fig. 30. Vertical transverse section of male plant, traversing an antheridial receptacle : a. c. air- 
chambers of thallus ; an. antheridia ; sm. rhiz. smooth-walled rhizoids ; tub. rhiz. tuberculate 
rhizoids ; v. s. ventral scales, x 10. 
Fig. 31. Median longitudinal section of young antheridial receptacle: a. c. air-chamber; 
an. 1, an. 2, developing antheridia; p. pore; v. s. ventral scales, x 360. 
Fig. 32. Female plant, with two receptacles (carpocephala). x 2. 
Fig. 33. The same, after elongation of the carpocephalum-stalk. x 2. 
Fig. 34* Carpocephalum as seen from below, showing cut end of stalk with its ventral furrow 
and the slit-like opening of the sheath around each of the six sporogonia. x 12, 
Figs. 35-37. Cells in tissue of carpocephalum-stalk, as seen in longitudinal section before, 
during, and after its sudden growth in length, x 360. 
Figs. 38-41. Longitudinal sections of developing carpocephala : for description see text, x 6. 
Fig. 42. Horizontal section of young carpocephalum, corresponding with the stage shown 
in Fig. 38. The cells occupying the anterior margin of the outgrowth show active divisions, 
constituting at this early stage a single growing-point, which may be compared with that of the 
thallus, shown in Fig. 8. Below the row of initial-cells there stand numerous mucilage-hairs, shown 
in cross-section ; two of the ventral scales which curve upwards over the young carpocephalum are 
also shown in section, x 200. 
Fig. 43. Similar section of a later stage, showing dichotomy of the apex, a ‘ middle lobe ’ 
having been formed between the two growing-points, as in ordinary dichotomy of the thallus 
(cf. Fig. 9). x 200. 
Fig. 44. A still later stage : here each of the two growing-points has again undergone dichotomy, 
so that four growing-points have been established ; between these are the projecting ‘ middle lobes.’ 
x 200. 
Fig. 45. Part of a horizontal section through a carpocephalum with eight growing-points, four 
of which are shown, x 200. 
Fig. 46. Part of a longitudinal section through a carpocephalum of about the same age as that 
in Fig. 40, showing a young archegonium : a. c. air-chambers ; p. pores ; rhiz. tuberculate rhizoids 
springing from the lower surface of the receptacle, near the insertion of the stalk (rec. si.). x 200. 
Fig. 47. Horizontal section of receptacle bearing six nearly mature sporogonia : a. c. air- 
chambers of receptacle, now reduced in size owing to the pressure exerted by the growing sporogonia ; 
cal . calyptra ; caps . w. capsule-wall; rhiz. rhizoids; si. stalk of receptacle. x 75. 
Fig. 48. Longitudinal section of ripe sporogonium, showing the foot (/. ), seta (j.), and 
capsule (c.) ; the spores and the free elaters are omitted, in order to show more clearly the apical 
thickening of the capsule-wall and the apical and basal tufts of fixed elaters. x 60. 
Fig. 49. Apical portion of capsule-wall, showing the strongly thickened cells of the apical 
cap, in surface view, x 200. 
Fig. 50. Cells in upper half of capsule-wall, as seen from outer surface, x 200. 
Fig. 51. Cells in lower half of capsule-wall, as seen from outer surface, x 200. 
Fig. 52. Fully formed elaters : a, normal form; b, c, branched elaters. X 200. 
Fig. 53. Median section of spore at time of dehiscence of capsule, x 200. 
Fig. 54. Germination of spore (optical section) : rhiz. rhizoid. x 200. 
