354 BOTANICAL GAZETTE [ NOVEMBER 
and covered with fruit in all stages of development, the writer 
has never succeeded in finding any antheridial plants, although 
he has carefully searched all sorts of specimens, nor have any 
such ever been found on this coast to his knowledge. 
For convenience the subject-matter of this description will 
be grouped under the following heads: (a) structure and mode 
of growth of the frond; (4) morphology and development of the 
procarpic branches; (c) development of the group of procarps; — 
(@) minute structure of the procarps; (e) development of the 
cystocarp. The subjects included in the first two divisions will 
be treated in the briefest possible manner. At the end of the 
descriptions will be found a section which treats of the relation 
of the type of cystocarp found in Ptilota to that of allied genera, 
and also some remarks upon the physiological character of this 
method of carposporic reproduction. 
STRUCTURE AND MODE OF GROWTH OF THE FROND. 
The writer can add nothing to the thorough description of 
the structure of the frond of this genus first presented by Nagels 
(47), and later more exhaustively considered by Cramer (63). 
However, a short account seems necessary to make clear the 
morphology of the parts of the fruit. 
The branches of the frond, styled pinnz, consist of a central 
axial siphon of large oblong cells or segments covered by # 
thick cortex of small cells. A large apical cell (fig. 4 x) ter 
minates the axial siphon of the pinna, and by its repeated trans 
verse division new segments are added to the axial siphon. 
On the pinne, attached to alternate segments of the 
siphon, one on each side, are borne pairs of lanceolate s 
called pinnules. In this species the pinnules are usually uneq 
in size, one being quite small, and their distribution is such t ; 
when a certain segment bears its large pinnule on the right han 
side of the pinna, the next large pinnule above 0 
tructures — 
t below ae 
“a eee eas Se) gia 
attached to the left side of a segment. As the small pinnules : 
are borne opposite the large pinnules, upon the same segue 
their arrangement is of course exactly the same as th 
e latter. : 
