304 Bower. — Some Normal and A bnormal 
Figs. 23-57. Trichomanes alatum. 
Fig. 23. A still more advanced sporophytic bud still attached to the frond which 
produced it; /, leaf; st, stem. X 5. 
Fig. 24. Characteristic branched conical hair from frond of sporophyte. x 70. 
Fig. 25. Oophyte of Tr. alatum, showing the relations of protonema, pr , to 
the flattened expansions, the antheridia, an, and rhizoids, rh , also old sterigmata, st. 
x 3- 
Fig. 26. Tip of frond showing incipient outgrowth of single cells, x 70. 
Fig. 27. Similar outgrowth more advanced, so as to result in protonema- 
filaments. x 35. 
Fig. 28. Portion of a frond with branched rib, from the surface of which pro- 
tonemal filaments, a , b , c, have been formed, h , one of the branched conical 
hairs of the sporophyte. x 35. 
Fig. 29 Sporangium : a rhizoid, rh, and a protonemal filament, pr, have been 
formed, apparently from cells of the annulus, x 70. 
Fig. 30. Aposporous development from the apex of a pinna, v.b. ending of a 
vascular bundle of the sporophyte. Both limbs of the oophytic growth have 
produced numerous sterigmata, st, and gemmae, x 35. 
Fig. 31. Irregular oophytic outgrowth from margin of a frond, x 35. 
Fig. 32. Flattened prothallus, one layer of cells in thickness, with numerous 
marginal protonemal filaments, x 3. 
Fig. 33. Marginal protonemal filament, p, produced from a flattened prothallus, 
prth , and widening out at its apex into a second flattened growth, prth II. 
x 35- 
Fig. 34. A characteristic piece of protonema of Tr. alatum : each cell forms a 
lateral appendage, which usually develops as a rhizoid, r. At x is a young 
flattened expansion placed laterally, x 35. 
Fig- 35- A protonemal filament showing lateral extension, and division of cells 
by longitudinal walls : this is an early stage in the development of a flattened 
expansion, x 35. 
Fig. 36. A further stage of a development of a protonemal filament into a 
flattened expansion: note that in both of these cases, as also in Fig. 28, the 
expansion is terminal in position, x 70. 
Figs. 37-39. Apices of flattened expansions while young, showing arrangement 
of apical meristem. x 85. 
Fig. 40. A protonemal filament which has borne a terminal sterigma, st : 
a second is being formed laterally below it. x 70- 
Fig. 41. Sterigmata, s, and gemmae in various stages of development (I-IV). 
x 85 . 
Fig. 42. ditto, x 35. 
Fig. 43. Mature gemmae, b 4 - c (x 35) show the point of attachment to the 
sterigma, x. x 70- 
Fig. 44. Early stages of germination of gemmae, x 35. 
Fig. 45. A, B, Antheridia, external view: A terminal, B lateral, x 175. 
