42 Gardiner and I to. — On Mucilage-cells 
33) 1 . No resin-secreting hairs are present, and on the young 
lamina only woolly hairs are to be found. The mucilage- 
glands occur on both sides of the young leaf-base, and are 
unbranched and filamentous. All the cells of the filament 
are usually glandular, so that, unlike Blechnum occidental , 
there is here a row of secreting cells and not a single terminal 
gland (Fig. 34). The non-secreting woolly hairs are long and 
branched, and cover the young lamina with a dense felt which 
affords an excellent protection against extremes of tempera- 
ture (Fig. 35). The development of both forms of hairs is 
essentially the same, and it is only in their subsequent be- 
haviour that they so markedly differ. They first arise as 
outgrowths of epidermal cells which are subsequently cut off 
by a wall from the general cell cavity (Figs. 38 and 39). The 
small cell thus produced is the mother-cell of the hair, which 
soon divides freely and produces a long filament (Fig. 34). 
In the case of the mucilage-hairs the growth is strictly basi- 
petal, and the hair is almost always simple and unbranched. 
The woolly hairs on the contrary may also elongate by means 
of apical growth, and branching with them is the normal and 
usual phenomenon. The young cells contain each a nucleus, 
usually provided with two, or sometimes three, well-marked 
nucleoli, and several plastids. 
As the cells grow they gradually become vacuolated, and, as 
in Blechnum , the nucleus is situated on the inner side of the 
ectoplasm in the mature cell. At an early stage the plastids 
divide and soon produce numerous starch-grains (Figs. 34 and 
35), which in the young cells occur in the bridles of protoplasm 
stretching from the nucleus, and, later on, become distributed 
all round the primordial utricle. They then occupy a position 
similar to that of the nucleus. 
1 According to Prantl (see Sadebeck in Schenk’s Handbuch, Bd. i. p. 274) the 
outermost young leaves of each winter-bud become peculiarly modified and scale- 
like, having for their function the protecting of the youngest and innermost 
members. Since our research was undertaken in October 1886 and finished in 
April 1887, we were working principally upon winter-buds provided with the 
modified leaves. 
