1896 ] PROCARP AND CYSTOCARP OF PTILOTA 367 
remarks will be in the nature of a comparison of these two 
Pacific coast forms with P. serrata. 
STRUCTURE AND MODE OF GROWTH OF THE FROND. 
The structure of the frond of P. plumosa and its variety 
filicina isin all essentials identical with that of P. serrata. The 
differences that exist are purely minor peculiarities of size and 
shape of pinnules and pinne, color, habit, etc. The structure of 
the framework upon which the corticating filaments are laid is 
quite the same in both species, and the method of growth of all 
parts of the frond is absolutely identical in the two forms. 
MORPHOLOGY AND DEVELOPMENT OF THE PROCARPIC BRANCHES. 
There is a more luxuriant production of fruit in the Califor- 
nian species than on P. serrata. While procarpic branches. are 
hot rare on the pinnules of P. serrata, they are very commonly 
so situated in P. plumosa and P. plumosa filicina, and the 
Steater part of the fruit is to be found on those portions of the 
frond. The procarpic branches on the pinnules, from one to five 
in number, are usually situated along the inner edge of that 
Structure, where they take the place of the teeth found along the 
edge of sterile pinnules. The procarpic branches of the Pacific 
Coast forms are shorter than those of P. serrata, in P. plumosa 
Consisting of only five or six segments, and in P. plumosa 
licina of eight or nine segments, the number of course being 
Somewhat variable. The procarpic branches of the variety filicena 
are not only longer, but also stouter than in the typical form 
p lumosa, in keeping with the coarser texture of the frond. Occa- 
sionally a procarpic branch will itself bear procarpic branches, 
that is, a lateral branch from the axial siphon, instead of devel- 
ping into a vegetative filament, will give rise to a short branch 
"pon the end of which a group of procarps will be developed. 
DEVELOPMENT OF THE GROUP OF PROCARPS. 
The gr oup of procarps in its development follows exactly the 
same steps in P. plumosa and its variety as in P. serrata. A com- 
