346 BOTANICAL GAZETTE [MAY 
dichotomous. This view of the character of the branching was 
confirmed for O. vulgatum by Porravtt (11). 
The occurrence of the two methods of branching within this 
family has suggested the desirability of further examination of this 
feature. This investigation has accordingly been undertaken with 
a view to securing further data bearing upon the relation of the 
three genera to each other and of the family to other Pteridophytes. 
Ophioglossum 
PorraULt (11) made the first critical examination of the nature 
of the branching of O. vulgatum. He concluded that the branching 
is usually only apparent, and that it is due to the development of a 
stem bud upon a young root before the root has broken through the 
a OOCO 
Fic. 1.—Transverse sections of a branching rhizome of Ophioglossum vulgatum; 
only the xylem is shown; X7 
cortex of the parent rhizome. In a single instance true branching 
was found, and anatomical examination showed this to be dichot- 
omy. So far as the writer is aware, there is no record of branched 
rhizomes in other species of this genus. : 
Ophioglossum vulgatum.—In the examination of some 300 specl- 
mens of this species, five branched rhizomes were found. These 
were examined in serial sections, and in all cases the original stele 
has divided into two equal and similar steles (fig. 1). There can 
be no doubt that this is dichotomy, as contrasted with monopodial 
branching. The term “dichotomy” is here used ‘to denote that 
branching in which a stem divides into two equal stems, a5 in 
Lycopodium, and is not meant to imply an exactly equal division 
of the apical cell of the rhizome. 
Ophioglossum pendulum.—In the examination of some 100° 
rhizomes of this species, two branched specimens were found. As 
