and Helminthostachys zeylanica . 
55 
PLATE II. 
Figs. 24-29. Ophioglossum pendulum. 
Fig. 24. Vertical section of a young archegonium. ( x 375.) 
Figs. 25, 26. Vertical sections of two nearly mature but unopened archegonia. 
(x 375-) 
Fig. 27. Transverse section of the neck of an opened archegonium. ( x 375 -) 
Fig. 28. Prothallus bearing an embryo ( em. ). ( x 7 *) 
Fig. 29. Median longitudinal section of the embryo shown in the preceding 
figure. ( x 100.) 
Figs. 30-49. Helminthostachys . 
Figs. 30, 31. Two of the smallest prothalli of Helminthostachys found. ( x 7 *) 
Figs. 32, 33, 34. Three male prothalli. (x 7.) 
Fig* 35 - Prothallus bearing antheridia, and, nearer the apex, archegonia and an 
embryo. ( x 7.) 
Figs. 36, 37. Two female prothalli bearing embryos. ( x 7 -) 
Figs. 38, 39, 40. Diagrammatic median longitudinal sections of one of th» 
smallest prothalli, of a male prothallus, and of a female prothallus respectively, 
showing the relative proportions borne to each other by the vegetative and sexual 
regions, a. apex, /./. lobes of the vegetative region, an. antheridia, ar. arche- 
gonia, e. embryo. (Fig. 38, x 25, the others x 7.) 
Fig. 41. Median longitudinal section of the apex, showing the segmentation 
of the initial cell. ( x 200.) 
Fig. 42. Longitudinal section through the sexual region of a male prothallus. 
(x 25.) 
Fig. 43. Transverse section through the sexual region of a male prothallus. 
O 50 -) 
Fig. 44. Similar transverse section through the unlobed vegetative region of the 
same prothallus. ( x 50.) 
Fig. 45. Part of a longitudinal section of the vegetative region of a young 
prothallus, showing a young lobe. The shaded cells of the internal tissue contain 
the endophyte, (x 100.) 
Fig. 46. A single rhizoid containing a fungal hypha. ( x 200.) 
Fig. 47. Two rhizoids containing hyphae ; the tips of the rhizoids have broken 
down. ( x 200.) 
Fig. 48. The internal tissue of a young prothallus, showing the Fungus bearing 
numerous vesicles ; the intervening cells contain starch. ( x 375*) 
Fig. 49. Corresponding tissue from a slightly older prothallus; the Fungus 
is shrivelled and dead, while the cells of the prothallus are packed with starch, 
(x 375-) 
PLATE III. 
# 
Helminthostachys , 
Figs. 50, 51, 52. Vertical sections of young antheridia. (x 200.) 
Fig. 53. Transverse sections through a young antheridium about the same age 
as that in Fig. 52 ; a . through the wall ; b. through the mass of spermatocytes. 
( x 200.) 
