54 
Barber . — On the Structure and 
that in those parts which do not increase in thickness, viz. 
the stipes below the ridge and the hapteres, there is no 
formation of the hyphal tissue. Figs. 13 and 14 represent 
the hyphal tissue of the lamina. There appears to be 
another form in which this budding of cells occurs. In 
a longitudinal section through an older part of the stipes 
a central strand of small elongated cells and tubes is met 
with. The cells between this strand and the cortex are 
elongated and large ; they appear to be separated by inter- 
cellular spaces (Fig. 15), and the latter are in some cases 
crowded by small, rounded cells. The larger cells appear 
to be separated by rows of smaller ones ; but the rounded 
contour of the latter, their frequent wide separation, and their 
irregularity, show that they do not form a tissue. They 
remind one, indeed, at first glance, very forcibly of thyloses. 
The large cells have many pits upon their walls, and the 
formation of a protrusion appears to take place over or at one 
of these pits. 
The epidermal cells usually contain only one nucleus. This 
is not the case with the other cells of the plant. A rapid 
increase of nuclei seems to be the normal course of events, 
and in some of the older cells thirty or forty may readily be 
counted, sometimes arranged in rows to the number of fifteen 
or sixteen (Fig. 16). In some cells each nucleus is surrounded 
by a group of chromatophores (Fig. 17). 
It appears to me that there is some misconception as to the number of nuclei 
present in the cells of brown seaweeds. Zimmermann, in his work on ‘ The Mor- 
phology and Physiology of the Plant Cell,’ dismisses the group with the following 
statement : — ‘ Among the Phaeophyceae Schmitz always found only one nucleus in 
each cell : only in the hair-cells of the conceptacles of Cystoseira barbata did he 
observe frequently several nuclei 1 2 .’ This would seem to imply that Schmitz had 
made a study of the group. But Schmitz’s words show that he examined only 
a few forms ; and these were mostly simple ones. He writes : ‘ Among Phaeo- 
phyceae I have also found the vegetative cells to be always uninucleate in the 
species of Cladostephus, Halopteris, Sphacelaria , Ectocarpus, and Discosporangium 
which I examined. The same holds good for Aglaozonia replans, Cr. Multipli- 
cation of nuclei in single cells is not, however, entirely wanting among the brown 
Algae, as is proved by an observation on Cystoseira barbata V ... . There does not 
1 Schenk’s Handbuch, iii. 2, p. 518, 1887. 
2 Verh. d. naturh. Ver. Bonn, 1880, p. 128. 
