262 MR. J. R. VAIZEY ON THE ANATOMY AND 
On the Anatomy and Development of Sporogonium of the 
Mosses. By J. Rzxworps Vaizty, B.A., St. Peter's Coll., 
Cambridge. (Communicated by S. H. Vınzs, F.L.S.) 
[Read 20th January, 1887.] 
(PrATEs IX.-XII.) 
I. POLYTRICHACEE. 
1. INTRODUCTION. 
Tue work, of which this is the first instalment, was undertaken 
with the view of showing that the Muscinee are not separated 
from the Vasculares (Pteridophyta and Phanerogamia) by so 
great a gap as has been usually supposed *. . 
The histology and morphology of the sporophyte t in the Mus- 
cines being almost unknown, it seemed that an investigation of 
that structure was highly desirable, and that it would serve to 
further elucidate the relations existing between the Muscineæ 
and other groups of plants. With this end in view these inves- 
tigations were commenced. 
The Polytrichaceæ were chosen as the starting point, as they 
are easily obtained, and their large size makes the examination of 
minute structure in them easier than in most of the other com- 
moner Orders of the Musci. References, however, will be made 
to the structure of the sporophyte as found in other Orders and 
in some of the Hepatice. By referring to the structure of forms 
other than those of the Polyirichaces it becomes possible to 
distinguish the charaeters peculiar to that Order from those 
which are typical of the whole of the Musci. 
A comparison of the structure of the sporophyte of the 
Musci with that of the Hepaticæ, and of both the Hepatice and 
Musci with the Vasculares, leads to certain speculations in re- 
gard to the phylogeny of these groups. 
Before recounting my own observations, I have thought it 
desirable to give a brief outline of work which has already been 
done. 
In 1782 Hedwig (8) 1 gave the first account of the Musci which 
* On this point cf. Goebel (5), p. 401, and Bower (2), pp. 604, 605. 
t On the use of this term generally see Prof. Bayley Balfour's (1) note, in 
which he justifies its use and that of the corresponding term oopAyte. 
1 The numbers in parentheses following the names of authors refer to the 
Bibliography on pp. 282, 283. 
