Inter nodal Vascular Strands of Equisetum. 13 
Milde’s figures of the internodal bundles of the aerial stems shows 
tha in E. mexicanum , Milde, E. Schaffneri, Milde and E. Icevigatum, 
A. Braun the lateral bands of metaxylem abut on the carinal canal 
and are, therefore, in connection with any of the earlier-formed 
tracheides which may persist at the edge of the carinal canal. 
Text-Fig. 2 a. and b., adapted from Milde (12, PI. 23, Fig. 7 and 
PI. 32. Fig. 5) show this condition in the two last mentioned 
species. Milde’s figures of similarly situated bundles in E. Martii, 
Milde and E. giganteum , L., though unsatisfactory, because drawn 
on a very small scale, seem to show that in these species also the 
lateral bands of metaxylem are, sometimes at least, in contact 
with the canal resulting from the disorganization of the first-formed 
tracheides (12, PI. XX, Fig. 3, and PI. XXI, Fig. 4). Again, 
Milde’s figures of the internodal bundles of the aerial axes of 
E. xylocheetum, Mett. and E. debile, Roxb. show that in these 
species one of the lateral groups of metaxylem may come into 
contact with the edge of the carinal canal, while the other may 
a. b. 
Text-Fig. 2. (a) Transverse section of the vascular bundle of the aeria 
stem of E. Schaffneri , after Milde, x 176. (b) Transverse section of the 
vascular bundle of the aerial stem of E. laevigatum, after Milde, x 176. 
remain separated from it either by a single parenchymatous cell or 
by a few such cells. Text-Figs. 3 a. and b. are adapted from 
Milde’s figures of such bundles in E. xylochcetum and E. debile 
respectively (12, PI. XIX, Fig. 8 and PI. XXVI, Fig. 17). Qu^va 
(14, p. 23) has remarked that in E. litorale Kuhlew the vascular 
bundles below the node assume a remarkable appearance owing 
to the linking up of the lateral bands of metaxylem at the edge of 
the carinal canal. His figure 21 shows that this species possesses 
locally a bundle which is essentially similar to the types of bundle 
depicted in Text-Fig. 2 and 3. Text-Fig. 4 a. is from a preparation 
of one of the upper internodes of the cone-bearing stem of 
Equisetum giganteum. The lateral groups of metaxylem are here 
almost in contact with the carinal canal; between them lies an 
irregular band of tracheides, broken in the middle and on one side 
