Anatomy of Solenostelic Ferns. 733 
J. Smith 1 in the section Leucostegia under the synonym of 
L. hirsuta , and this arrangement is quite in accordance with its 
vascular structure. The other exception is Davallia pinnata , 
the stele of which exhibits a structure intermediate between 
a solenostele and the Lindsaya- type of stele. This plant has 
been removed from Microlepia by H. Christ 2 and given 
a section to itself : Wibelia. The anatomy agrees with this 
separation, and indicates a closer relationship to the Lindsayas 
than to Microlepia. Davallia Novae-Zelandiae ( Leptolepia , 
Met.) is regarded by J. Smith and H. Christ as a species of 
Microlepia , but in the ‘ Synopsis Filicum 5 it is included in 
the section Leucostegia. Since, however, it proves to be 
typically solenostelic, and the section Leucostegia itself is 
a predominantly dictyostelic one, the anatomy gives un- 
qualified support to the two former authorities. 
Probably all the species of the genus Hypolepis are soleno- 
stelic, although the four species mentioned in this paper are the 
only ones in which the anatomy has been sufficiently described. 
Prantl 3 * , in 1892, proposed to divide the Polypodiaceae into 
four great tribes : the Aspidieae, the Asplenieae, the Pterideae, 
and the Polypodieae. At the same time he founded the sub- 
tribe Dennstaedtiinae to include the genera Dennstaedtia. 
Microlepia , Leptolepia , Saccoloma and Hypolepis , which he 
regards as containing all the most primitive species of his 
first tribe, the Aspidieae. It has been shown above that 
essentially the same type of primitive vascular system is 
to be found in every species of this sub-tribe in which the 
anatomy is known. Therefore, as regards the primitive 
nature of the sub-tribe as a whole, Prantl receives strong 
support from the anatomy, but to decide whether all these 
genera belong to the base of one and the same line of descent, 
or not, is another and a very difficult question ; as he himself 
acknowledges. Dennstaedtia and Microlepia certainly appear 
1 Historia Filicum, 1875. 
2 Die Farnkrauter der Erde. Jena, 1897. 
3 Das System der Fame, Arbeiten aus dem K. Bot. Gart. z. Breslau, Bd. i, 
Heft i, 1892. 
