is Fs oe oye 
65 
ON PROTOPLASMIC CONTINUITY IN THE FLORIDEZ. 
By Tuomas Hicx, B.A., B.Sc. 
(Puates 243 & 244.) 
(Concluded from p. 38). 
Polysiphonia nigrescens agrees in the main, in structure and si 
m 
As the cell-walls of the central siphon thicken, they do 
so uniformly, so that the protoplasmic body retains more or less 
of its Sic eeeisewy shape. 
rotoplasmic continuity is well ae and may be traced 
thronghout the whole thallus. The s of the different siphons 
have their contents connected by ictere Bi threads whi ass 
thro , and central sip are 
connected with those of the cortical siphons by lateral processes. 
hese processes are situated about the middle of the cell and are 
comparatively short, owing to the small amount of thickeatts the 
undergo. 
siphonia atro- Agree has such close resemblance to the 
preceding 8 species that it will be no marvel that it agrees with it 
3 
matter of poonlaahis continuity. The cells of the 
central siphon are of a similar shape and have similar connections, 
both with one another and with the cells of the cortical siphons. 
let byssoides, P. tenella and P. formosa present similar 
phenom 
8. CEeRamium. 
The eens Ceramium has a structure differing from that of Poly- 
siphonia i in many respects, but agre eing with it in presenting a 
thallas consisting of a central axis or siphon of cells, clothed to a 
greater or less extent by a cortex. The latter, however, originates 
in a different manner, being composed of cells or ae boners 
) 
nt to the 
ament. The cortex formed by these branches dcotmuouitlg ree 
so thick that it is impossible to make out the organisation of the 
central siphon without the aid of transverse and lo ngitudinal 
sect Even on the smallest branchlets the nodal cortications 
of reagents and some y the help 
however, it may be See sutabbiched that protoplasmic 
— exists here quite as regularly as in the genera previously 
consl d. 
Ceramium acanthonotum has the ears: — of the 
central cells connected as shown in Plat 8, fig. 6. In the 
y' i branchlets the protoplasm of ee eel appears in optical 
longitudinal section, as a lozenge-shaped mass enclose a more 
or less thickened wall. The cortex fills up the paren ai <tebinedn 
Journat or Borayy.—Vou. 22. [Mancu, 1884.) F 
