238 MR. A. C. SEWARD AND MISS S. 0. FORD ON 
recently been advanced by Jeffrey * and elaborated by Faull +, which leads to the 
conclusion that “the cauline vegetative system of this family is neither primitive nor 
anomalous among the Filicales.” This opinion is in striking contrast to that of Zenetti T, 
who speaks of the stelar structure of all other Ferns as “ himmelweit verschieden " from 
that of the Osmundaceæ. 
With the exception of the description given by Faull of certain anatomical features 
of the stems of Todea barbara and the filmy species 7. superba, our knowledge of the 
anatomy of the Osmundacez is almost confined to the genus Osmunda. The work 
embodied in the present paper was undertaken with a view of ascertaining how far the 
genus Todea agrees anatomically with Osmunda, and in order to obtain evidence which 
might throw light on certain peculiar histological features described by Zenetti in his 
excellent paper on Osmunda regalis. The opinion most widely held by botanists is that 
the Osmundacez are in many respects intermediate between the leptosporangiate Ferns 
and the Marattiacez. The occasional occurrence of synangia $, the large and compara- 
tively thick-walled sporangia |, the stipular wings of the leaf-stalk bases fl, the nature 
of the apical meristems and certain characters of the gametophyte **, constitute some of 
the grounds on which this view is based. We have confined our attention to the 
anatomy of the sporophyte of three species of Todea— T. barbara, Hook. f., T. superba, 
Col, and T. hymenophylloides, Rich. & Less.—and to a critical examination of the 
available palzeobotanical data bearing on the past history of the family: 
EXTERNAL FEATURES. 
| The genus Todea is represented by :—7. barbara, occurring in South Africa from the 
Cape to the Drakenberg Mountains, in Eastern Australia from Queensland to Tasmania, 
and in the North Island of New Zealand ; T. (8 Leptopteris) Wilkesiana, a small tree-fern 
of the Fiji Islands, Samoa, the New Hebrides, and New Guinea: T. (§ L.) superba, a New 
Zealand species, characterized by a short erect stem; 7. ($ L.) hymenophylloides, very 
similar to 7. superba, and also confined to New Zealand; T. (§ L.) Fraseri, from New 
South Wales and New Caledonia ; and some authors retain T. (§ L.) Moorei as a name ot 
specific rank for a form confined to Lord Howe's Island. 
In the ‘Synopsis Filicum’ ++ Todea is described as being represented by four species— 
T barbare, placed in the section Hutodea; and three filmy species, T. Fraseri, T. hymeno- 
phylloides, and T. superba, included in the section Leptopteris. Presl proposed the 
mame Leptopteris for the filmy species, which he considered should be generically 
separated from Todea barbara ; but Milde in 1871 ii showed that some of the characters 
= which Presl based his genus Leptopteris were of little value. Among recent writers 
; rist $8 and Diels [||| both retain , eptopteris as a distinct genus. The question of the 
union of both filmy and coriaceous forms in one genus or their separation as Leptopteris 
* Jeffrey (1901). 
| + Faull (1901). 
$ Bower (1899), p. 40, pl. 3. fig. 51. 
€ Zenetti (1895). 
|| Bower (1891), pl. 7. figs, 6-8 “g 88 
** Kny (1872); Luerssen (1874); Campbell ebd waa E ower (1885). 
it Milde (1871). (1874); Campbell (1895) (1899) ; Heim (1896). tt Hooker & Baker (1868), p. 426. 
$$ Christ (1897), p. 332. — [ij Diels (1900), p. 372. 
