3 83 
Anatomy of the Opkioglosseae. 
practically identical with a collateral bundle. This relation 
between leaf-trace and root is not, however, without excep- 
tion 1 , and the structure seen in several sections has much 
more the appearance of a root-bundle abutting on a stem- 
bundle at or near the part forming the downward prolonga- 
tion of the leaf-trace. It is certainly difficult to follow the 
tracheides of a leaf-trace down as far as the insertion of the 
corresponding root ; but in one series of transverse sections 
the root-stele (as also happened in several other cases) was 
attached quite to the lateral edge of a stem-bundle, and here 
appeared to be connected with commissural elements rather 
than with leaf-trace tracheides. 
On Holle’s interpretation, the twisting of the bundle, 
described above, would also seem purposeless, and would 
amount to this : — the leaf-trace, instead of simply bending 
outwards without any twisting, when it would obtain the 
correct orientation for the root, bends sharply through about 
90°, and then bends back again through the same angle in 
passing through the cortex. 
Series of sections were also cut through the root-stele in 
the cortex of the stem of Botrychium Lunar ia. When the 
orientation could be clearly made out, the xylem-plate, in the 
case of diarch roots, appeared to be horizontal 2 just before 
joining the stem-bundles ; that is, there was a protoxylem- 
group on each side of the vertical plane. If the protoxylem 
on one side of the vertical plane were abortive, and the two 
phloem-masses were to fuse on the other side (a kind of 
1 Bower, l.c., p. 67. ‘This regularity, however, does not hold for the lowest 
leaf of a shoot, nor is the regularity always maintained.’ Holle ( 1 . c., p. 314) also 
mentions that the first two leaves have no roots belonging to them. Rostowzew 
(Recherches sur 1 ’ Ophioglossum vulgatum, in Oversigt Videnskab. Selskabs, 
1891 (No. 2, p. 72), states that very rarely there are two roots to a leaf; and 
Prantl ( Helminthostachys zeylanica, u. ihre Beziehungen zu Ophioglossum u. 
Botrychium , Ber. deutsch. bot. Gesellschaft, i, 1883, p. 156) also calls in question 
the relation between leaves and roots as described by Holle. 
2 This agrees with Holle’s observations on this and two other species of the 
genus, 1 . c., p. 268 ; and with those of Van Tieghem on Botrychium Lunaria 
(Symetrie de structure des plantes ; Annales des Sciences Nat., Bot., v. ser., t. xiii, 
p. 105). 
