Inter-Relationships of the Higher Bryophyta. 37 
IX. INTER-RELATIONSHIPS of the HIGHER BRYOPHYTA 
(SPHAGNALES, ANDREA3ALES, TETRAPHIDALES, 
POLYTRICHALES, BUXBAUMIALES, EU-BRYALES). 
X N seeking for a starting-point for the evolution of the higher 
Bryophytes, or Mosses, one is struck by the remarkable 
resemblances between the Sphagnales on the one hand and the 
Anthocerotales and (to a smaller extent) the Jungermanniales on 
the other. Apart from the flat thalloid protonema, which suggests 
comparisons with both the lower Jungermanniales and the Antho¬ 
cerotales, Sphagnum resembles the former group in the structure 
and dehiscence of its antheridium, and in the early development of 
the sporophyte. However, apart from the fact that in Sphagnum 
the young antheridium grows by an apical cell, instead of showing 
the intercalary growth characteristic of the Liverworts, it may be 
noted that in Buxbaumia the antheridium is very similar to that of 
Sphagnum. Buxbaumia is in many respects primitive, and it is 
interesting to note that in this genus the young leaf, instead of 
growing by an apical cell as in other Mosses, shows the bilobed 
condition characteristic of the Acrogynae. It would appear that in 
Sphagnum the sexual organs and the leaves have departed from the 
intercalary mode of growth found in Liverworts, and show the 
apical cell growth found in the higher Mosses, but the sporogonium 
still undergoes intercalary growth and in its earliest stages presents 
a close resemblance to the embryo of Jungermanniales. The 
striking similarity between Sphagnum and the Anthocerotales in 
the origin and form of the archesporium suggests that Sphagnum 
has probably arisen from a synthetic ancestral type which combined 
