ANATOMY 459 
reduced from some more complex structure:! in the observations relating 
to the Ophioglossaceae there is no necessity to adopt this view, which 
does not readily accord with the fact that the monarch condition appears 
at the very base of the root, both in Botrychium and in Ophioglossum. 
I am disposed to regard the monarch state as primitive. But whether 
they be primitive or reduced does not materially affect comparison : 
the family is clearly one with great instability of root-structure, and 
there are in a number of cases monarch roots which dichotomise. In 
these respects the Ophioglossales find their nearest correlatives among the 
Lycopodiales. Comparison should also be made with the Sphenophyllales: 
but the Psilotaceae are rootless, and the knowledge of the root-system of 
Sphenophyllum is still very obscure: apparently they were diarch, with 
secondary thickening,? a condition not far removed from that described 
for the roots of OpAzoglossum, but still more clearly seen at the base of 
the roots of Gotrychium; for here it has been shown by Boodle that 
secondary thickening of the root may occur. Thus in the Ophioglossaceae 
there are unmistakable points for comparison with the Lycopodiales and 
Sphenophyllales. On the other hand, the larger polyarch roots in the 
family show structure reminiscent of certain Ferns, and especially of the 
Marattiaceae. 
The stock of the Ophioglossaceae originates directly from the embryo, 
or it may be formed indirectly as a result of adventitious budding. The 
young axis has been examined in all three genera, and in the first 
instance the vascular tissue is found to be centroxylic, either with a 
quite solid core, as in some seedlings of Helminthostachys,* or in others 
it may have a central pith from the first, and this seems to be the case 
in Botrychium. In Ophioglossum the axis of the embryo, as described 
by Bruchmann in O. vulgatum,® is very short, and no facts are at hand 
as to its stelar structure. But Bruchmann states that the development of the 
embryo coincides in all its later particulars with that of the adventitious 
buds, and these have been described and figured by Rostowzew.’ The 
vascular tissue, on entering one of these buds from the parent root, “forms 
a central cylinder, which dilates and becomes concentric (Fig. 236, No. 4): 
higher up it takes the form of a funnel, which is filled with parenchymatous 
pith: higher again the cylinder produces on one side a mesh from the 
‘lower angle of which the strand of the first leaf arises.” This description, 
together with the drawings (Fig. 236, Nos. 2, 3, 4), indicates at the start a 
protostelic state, or at least a stele with only small medulla. It thus appears 
1It will suffice here to mention Boodle’s teleological theory that the monarch structure 
of Opshioglossum is an adaptation for favouring the growth of adventitious buds on the 
roots. He himself quotes cases which do not bear out his view: his theory, moreover, 
seems to confuse cause with effect. 
2Seward, Fossil Plants, i., p. 399. 3 Z.c., p.» 388 and Fig. 14. 
4Lang, Anz. of Bot., vol. xvi., p. 42. 5 Jeffrey, Zc., p. 21, Fig. 61. 
6 Bot. Zeit., 1904, p. 240. 7Z.c., Pl. 1, Figs. 2, 3, 4. 
