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ANATOMY 459 



uced from some more complex structure : l in the observations relating 

 o 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, 2 a condition not far removed from that described 

 'or the roots of Ophioglossum^ but still more clearly seen at the base of 

 e roots of Botrychium for here it has been shown by Boodle that 

 ondary thickening of the root may occur. 3 Thus in the Ophioglossaceae 

 ere are unmistakable points for comparison with the Lycopodiales and 

 phenophyllales. On the other hand, the larger polyarch roots in the 

 mily show structure reminiscent of certain Ferns, and especially of the 

 rattiaceae. 



The stock of the Ophioglossaceae originates directly from the embryo, 

 it may be formed indirectly as a result of adventitious budding. The 

 ung axis has been examined in all three genera, and in the first 

 stance the vascular tissue is found to be centroxylic, either with a 

 ite solid core, as in some seedlings of Helminthostachysf or in others 

 may have a central pith from the first, and this seems to be the case 

 Botrychium.^ In Ophioglossum the axis of the embryo, as described 

 Bruchmann in O. vulgatum? is very short, and no facts are at hand 

 to its stelar structure. But Bruchmann states that the development of the 

 bryo coincides in all its later particulars with that of the adventitious 

 uds, and these have been described and figured by Rostowzew. 7 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 



1 It will suffice here to mention Boodle's Ideological theory that the monarch structure 

 of Ophioglossum 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. 



2 Seward, Fossil Plants, i., p. 399. 3 Z.r., p. 388 and Fig. 14. 



4 Lang, Ann. of Bot., vol. xvi., p. 42. 5 Jeffrey, /.r., p. 21, Fig. 61. 



6 Bot. Zeit., 1904, p. 240. 7 Z.r., PI. i, Figs. 2, 3, 4. 



