326 BOTANICAL GAZETTE [NOVEMBER 
branches are sometimes postical, sometimes lateral ( fig. 7), and 
sometimes occupy a position between postical and lateral. In 
fact, the lateral position is the most frequent and is almost inva- 
riably assumed by the sexual branches. In O. Grdbsiae and in 
O. denudatum, as well as in the recently described O. cavifolium 
Steph.” of Japan, lateral branches are also of occasional occur- 
rence. That the origin of these branches is really postical and 
their lateral position is due merely to displacement, as Leitgeb 
maintains is the case in Plagiochila, is not improbable, but it has 
not been determined with certainty. It is clear, however, that 
this theory of displacement from the postical segment cannot 
apply to the genus Anomoclada, where all the branches except 
the flagella are distinctly antical in position. In this genus it is 
perfectly apparent that the branches arise from the lateral seg- 
ments, and the difference in position between such an antical 
branch and the lateral branches in Odonotoschisma Macounit is 
really not very great. 
The lateral branching which occurs in Cephalozia Turneri and 
in some of its immediate allies was used by Spruce?3 as the 
essential character of his subgenus Prionolobus, a group which 
Schiffner has since raised to generic rank. On the same grounds 
O. Macounii might be separated generically from O. Sphagnt, but 
such a separation would be very artificial, especially when we 
take into consideration the inconstancy in the position of the 
branches in O. Macounii. In fact, the generic claims of Prionolo- 
bus are not above criticism, on account of the occurrence of both 
postical and lateral branches in certain undisputed species of 
Cephalozia. 
It is probable that the position occupied by intercalary 
branches, and especially by those of adventitious origin (7. ¢., by 
those arising from differentiated axis-cells which have reassumed 
an embryonic character), is largely influenced by the conditions. 
under which a species develops. This statement would apply 
especially to plastic species; of which O. Macounii seems to offer 
an example, but it would also apply to the plastic ancestors of 
** Bull. de l’Herb. Boissier 5: 102. 1897. 
*3 Hep. Amaz. et And. 508 (footnote). 1885. 
A a Nira = ma ha i 
