358 
borne principally on the edge but also on the flat side of the pinnulæ. They were 
cut off in a number of 2 or 3 by inclined walls from the low stalk cells (Sperma- 
tangien-mutterzellen SVEDELIUS) which seem 
to contain chromatophores (Fig. 292). 
The cystocarps develop terminally on short 
pinnulæ and are surrounded by a whorl of 
sterile branches. The procarps have been de- 
scribed by Davis and PhHiıtLirs, but the inter- 
pretations of these authors are diverging. Upon 
the end of the fertile pinnæ arises a group of 
short cell-filaments each ending in a hyaline 
hair. According to Davis (1896) these are 
groups of procarps the number of which is 
variable, though typically 5. Davis interpreted 
B all the hyaline hairs as trichogynes, but as he 
has never found spermatia adhering to them 
and as he has not observed antheridia he sup- 
posed that the cystocarp develops apogamously. 
Pnırrırs (1897) arrived at another interpreta- 
tion, the 4-celled external short-celled branch 
being the only true carpogonial branch while 
the others are only vegetative structures. KYLIN 
who has recently (1923) carefully studied the 
development of the pro- 
ig, 292 9 
; FER ERP te i carps arrived at the 
Plilota plumosa. Å, pinna with antheridia. B, pin- å 
nula with antheridta and two spermatia. 350 : 1. same conclusion. He ob- 
served the fertilisation 
and the transmission of a small sporogenous cell to the auxi- 
liary cell which is cut off from the basal cell immediately 
after fertilisation. In one specimen dredged in the Sound 
north of Helsingor in June I found procarps before fertilisation. 
The trichogyne was usually thicker than the sterile hairs and 
frequently swollen at the top. It is strange that these vege- 
tative hairs are normally present while vegetative hairs are 
otherwise wanting in this species. 
The gonimoblast according to Davis consists of 2—5 
Fig. 293. 
Ptilota plumosa. Carpogonial 
nearly globular lobi which are quite separated from one an- branch (to the right) and 
> à AE R & surrounding sterile filaments 
other but are all attached to the central cell. The lobes are — ending in hyaline hairs. 
as a rule in widely different stages of maturity. According to 390 :1. 
Kyrın (p. 61) the basal cell (“Tragzelle”) fuses more or less 
with the auxiliary cell and the first cell of the gonimoblast. The number of the 
involucral branches varies up to at least 8. 
