Bower . — Studies in the Phytogeny of the Fi lie ales. 451 
true Cyatheoid Fern bore runners like those of Lophosoria or Metaxya , 
these would probably be solenostelic. The fact that they may be is 
illustrated in the case of Hemitelia setosa. On a large plant of that species, 
in the Edinburgh Botanic Garden, there was borne an underground runner, 
which after a horizontal course turned above ground as an upright leafy 
shoot. I here acknowledge the kindness of the Director in having it cut off 
close to the main stock and sent to me. It was over i-| inches in diameter, 
and very fleshy, though covered by an external band of brown sclerenchyma. 
But when cut in transverse section it showed an advanced type of Cyatheoid 
structure, with dictyostele showing commonly three leaf-gaps in one trans- 
verse section ; there were also numerous strands forming a medullary 
system. Thus the thick runner carried no special interest, as bearing on 
the present question. 
A second runner of smaller size was, however, found arising laterally 
from the larger runner, and presenting externally an appearance not unlike 
those of Lophosoria. This was cut into sections, and was found to be 
solenostelic (Fig. 10). It will be noted that in the central medulla two 
small strands are present, showing that even at an early stage in a small 
runner the medullary system may be constituted (m.s.). A special interest 
attaches to the vascular supply at the base of the small runner for com- 
parison with that in Lophosoria. So transverse sections were cut to its 
extreme base, and it was found that the solenostele did not close at inser- 
tion on that of the main shoot, but remained an open ring with a massive 
cylinder of pith. This, in the case in point, was still traversed by the two 
small strands, which passed down through the open tube to connect with 
the medullary system of the main axis. Except for the existence of these 
medullary strands, the arrangement is essentially as in Lophosoria. But the 
presence of a medullary system may be held as a feature of advance, which 
has a parallel in other characters of Hemitelia , such as the greater dis- 
integration of the leaf-trace, the presence of dermal scales, of a partial 
indusium, and a basipetal succession of the sporangia in the sorus, as 
against the more concrete leaf-trace, the absence of scales and of any 
indusium, and the simultaneous origin of the sporangia in Lophosoria . 
Thus, though Hemitelia setosa shows these characters of advance, it also 
shows the interesting primitive feature of solenostely in its small runner. 
But this is not the first example of pronounced solenostely which 
has been described among Cyatheoid Ferns with a basipetal sorus. The 
old observations of Stenzel on Alsophila acideata 1 show an example which 
corresponds very closely with those above described. From an old stock 
numerous runners arise, each related to a leaf-base as in Lophosoria ; while 
their anatomy showed at least in their lower region an uninterrupted tube. 
These runners, as in Lophosoria , usually turned downwards at first, and 
1 Verhandl. d. K. Leop. Carol. Akad. d. Naturforscher, 1861, p. 16, Tab. I, II. 
