1915] PETRY—OPHIOGLOSSACEAE 363 
Summary 
1. Branching of the rhizome of Ophioglossum vulgatum and O. 
pendulum is dichotomous; there are no axillary or adventitious 
buds on the rhizome. 
2. Axillary buds are regularly present in five species of Botrych- 
ium. 
3. The vascular connections of the branches in Botrychium vary 
widely with the species and with the individual specimen. It is 
concluded that the details of the vascular supply of the branch are 
controlled by the conditions of development and are therefore of 
little or no phylogenetic importance. 
4. In wounded rhizomes of B. obliquum, renewed activity of the 
cambium produces considerable masses of accessory xylem; the 
pith frequently develops sieve tubes and a cambium which produces 
secondary xylem in quantity; the pericycle often produces sieve 
tubes and secondary xylem. It is concluded that in this species 
any stelar tissues capable of growth may produce vascular elements 
under the influence of an injury. 
5. The axillary bud of B. obliquum arises as a plate of meriste- 
matic cells on the adaxial face of the base of the very young leaf; 
it develops without differentiation into a plate of meristematic 
tissue one or two cells in thickness and 50-60 cells in area, which is 
buried by overgrowth of surrounding tissue. 
6. The data secured is in agreement with the evidence pointing 
to a relationship of the Ophioglossaceae to the primitive ferns, 
especially the Zygopterideae. 
SYRACUSE UNIVERSITY 
SYRACUSE N.Y, 
The writer wishes to acknowledge the kindness of Professor 
Joun M. Coutrer in placing the facilities of the Hull Botanical 
Laboratory at his disposal; and to express his thanks to Dr. W. J.G. 
Lanp for material of Trichomanes. 
