36 
F. O. BOWER. 
On the Developmej^t of the Concept acle in the FucacEvE. 
By F. O. Bower, B.A.., Trinity College, Cambridge. 
With Plate V. 
The first careful notice of the conceptacle which I have 
met with is that in the ^ Phycologia Generalis ’ of Kiitzing 
(1843). 
He describes (p. 98) it as a roofed-in sorus (einges* 
tiilpter sorus) ; while the tissue which lines the cavity is, he 
says, nothing else than a slightly modified continuation of 
the limiting tissue^ (cortical schicht). 
Speaking (p. 92) of the Fasergrubchen ” (a word which 
has as yet no English equivalent), he says they seem to stand 
in a certain relation to the conceptacle (Hiillenfrucht), 
although they are found on such of the brown seaweeds 
as have no conceptacles (cf. Alaria esculenta). 
Agardh (^Species et ordines Algarum,’ 1848, vol. i, 
p. 101) suggests that the Fasergrubchen ” may be the 
equivalent of the conceptacles (scaphidia) in the fertile part 
of the plant. 
Sachs Lelirbuch,’ 1874, p. 283) remarks that the layer 
of cells lining the cavity is a continuation of the outer limit- 
ing layer of the Thallus. 
The first attempt at an accurate description of the de- 
velopment of the Fasergrubchen or conceptacle was made 
by Reinke (^Bot. Zeit./ 1875; and ^ Nachrichten der K. 
Ges. d. Wiss. zu Gottingen,^ 1875, p. 230). His results 
were republished in PringsheinTs ‘Jahrbuch,’ x, 1876, 
p. 317. 
Speaking of Fucus vesiculosus, he says (p. 337) that the 
Fasergriibchen,^’ which he seems to take as the type of 
these structures, originates, as seen from above, by a sepa- 
rating of four or five neighbouring cells of the limiting tissue 
from one another. He compares this process with the forma- 
tion of the resin passages in the Coniferse. The ‘‘ intercel- 
lular space” thus formed is filled with mucilage. Longitu- 
dinal sections showed him that not only cells of the limiting 
tissue, but also cells of the subadjacent cortical tissue, separate 
‘ RostaGnski (‘ Beitrii^e zur Kenntniss der Tange,’ Heft i, 1876, p. 5) 
has already objected to the use of the term “epidermis,” in the case of 
Fucus, on the gropd of the outermost layer of cells being capable of con- 
stant tangential division. Pie uses the term “ aussenrinde,” which I pro- 
pose to render loosely by the term “ limiting tissue,” reserving the term 
“ cortical tissue,” for his “ innenrinde.” 
