НЕввтотт.— Morphological Notes on the New Zealand Giant Kelp. 553 
of the cambium layer increased in thickness, and finally met. Continued 
growth and the constant friction of the tissues may then have caused the 
adjoining tissues to unite, and so to appear finally as branches of one main 
stipe. 
The tissue of which the holdfast is composed is very elastic; when 
pulled away from the rock it contracts greatly, the lower layers contracting 
ost and drawing the upper layers over them. en washed up on the 
beach and left exposed the holdfast loses its water and contracts to a hard 
horny mass. 
Figures 3 and 4 show details of the anatomical structure of the holdfast. 
These sections were cut from a young specimen. The tissue appears to 
these cells is seen to contain a large nucleus. 
Below this again comes tissue (c), of small rounded cells, and this passes 
into the central tissue (d), consisting of large irregularly shaped cells with 
of the holdfast. Its cells contain some small round bodies (fig. 3, А) which 
stain a faint yellow with iodine; this is probably the Phaeophycean starch 
of Schmitz (Zimmermann). The presence of such bodies in the holdfast 
would support the theory presented by Harvey (1849, Introduction, p. xx) 
that the holdfast acts as the storehouse for reserve food, and may be com- 
(1885, p. 7) for D. Harveyi. Their function is probably protective. 
ections were also cut from older holdfasts. These had been exposed 
for some time to wind and sun, and had therefore lost much of their water. 
The outermost layer consisted of cubical-shaped cells, but the great part 
was composed of very irregularly shaped cells embedded in a horny matrix, 
to which the peculiar woody appearance of a cut holdfast is probably due. 
When such dried specimens are placed in fresh water they swell up 
enormously, but the constituent cells then present a very distorted appear- 
ica. 
In the holdfast growth is effected by a definite growing tissue (fig. 3, b), 
and in this it differs from stipe and lamina, in which growth is evidently 
(2. The Stipe. 
The stipe, as it arises from the holdfast, is cylindrical, but in most cases 
it gradually becomes flattened and passes into the lower portion of the 
frond. In other cases the original stipe continues its growth, retaining 
its cylindrical form, while it gives off secondary stipes along its axis. This 
is the pinnate arrangement mentioned by Hooker (1864, p. 654). The 
secondary stipes then bear the segments of the frond. A small plant ot 
