56 
Barber . — On the Structure and 
tissue below the ridge, although the cells of the central strand 
retain their elongated character (Figs. 18 and 19). 
The absence of the hyphal tissue below the ridge leads one 
to interesting speculations as to the use of this layer to the 
organism. The position of this tissue and the elongated 
character of its cells immediately suggest that it is of use in 
transport. As such it is regarded by those who have made 
a special study of the larger seaweeds (N. Wille) 1 . This idea 
is strengthened by the discovery of the perforated transverse 
plates by Wille and Will, as also by the close connection of the 
hyphal tissue with the sieve-tubes of Macrocystis (H. Will 2 ) 
and of Nereocystis (Oliver 3 ). 
The formation of the ridge seems to be very closely 
connected with the formation of the hyphal tissue. The 
great increase in size of the cells of this neighbourhood renders 
it necessary that large stores of material shall be hurried down 
the narrow stalk from the centre of assimilative activity. Such 
a need leads to the great increase of the path of transport at 
this point, and hence the almost immediate assumption of the 
oval form of the transverse section of the stem. As the ridge 
developes, a core of hyphal tissue accompanies it, thus render- 
ing possible the great development not only of the bulb itself 
but of the numerous hapteres, and, in the older plants, the 
masses of sporangia. 
The development of the hapteres commences like that of 
the ridge. There is, however, no bending out of cells, nor any 
formation of hyphal tissue. The transverse section of one of 
the hapteres (Fig. 20) reminds one forcibly of that of a phane- 
rogamic water-plant. There is a moderately developed cortex of 
smaller cells passing into the usual epidermal meristematic layer. 
The central larger part of the section is occupied by cells of 
two kinds — larger cells distributed at equal distances, and rows 
of smaller cells surrounding and separating them. The large 
cells call to mind the intercellular spaces of water-plants, but 
they are cells with protoplasmic lining, and many nuclei. In 
1 Berichte d. deutsch. bot. Gesellsch. 1885, P- 2 9 - 2 Bot. Zeit, 1884. 
3 Annals of Bot., vol. i. (1887), p. 95. 
