FROM THE NORTH-WEST AMERICAN COAST, 165 
Dr. Lyall has communicated numerous well-dried herbarium spe- 
cimens of the young plant, which well illustrate the progressive 
development of the frond. The youngest specimen sent has a 
stem two inches long, tipped by a bulbous vesicle 2-3 lines in 
diameter, carrying at its summit two falcate-lanceolate leaves, 
which show a tendency to split from the base upwards, the line of 
future separation being indicated nearly to the middle of each 
leaf. In the next stage the stem has grown but little; but the 
apical bulb has attained the diameter of 4—5 lines, and the two 
leaves have, by medial splitting, become four, of which two are 
perfectly free, and two still connate for a short space near the 
base—thus showing (as is also more clearly seen in older plants) 
that the fissure takes place both from the base upwards and from 
the apex downwards. Other specimens, in which the stem is 6-8 
inches long, the bulb 1-11 inch in diameter, and the leaves 14-16 
inches long, are not more advanced in subdivision than the first 
here described. The age and size at which splitting begins pro- 
bably depend on the depth at which a specimen grows, those in 
shallow water beginning to divide at an earlier age. All after- 
growth consists in the lengthening of the stem till it reaches from 
200 to 300 feet, in the increasing size and hollowing out of the 
apical vesicle till it becomes six feet or more in length, and in 
the multiplieation of leaves, by continual bisection, until there 
results a huge, geminate tuft of foliage, always separated at base 
into two distinct bundles by the true apex of the vesicle, from 
which no leaves spring. Eventually each leaf is 20-30 feet long. 
In Dr. Lyall’s larger herbarium specimens there are eight leaves, 
each partially bisected. 
ll. Alaria Pylaii, Grev. ; Harv.; Ner. Bor. Amer. i. p. 89. 
On stones at the mouth of the Esquimalt Harbour and St. Juan de 
Fuca, Dr. Lyall & C. Wood. 
Most of the specimens are immature. The few that produce 
pinnz have them broadly obovate, broader in proportion to their 
length than on specimens from Newfoundland. In other respects 
the plants agree. 
12. Alaria marginata, Post. & Rupr.? Harv.; Ner. Bor. Amer. i. p. 89. 
Esquimalt Harbour, &c. 
The specimens are immature, without pinne, though some are of 
large size, 5-6 feet long. Even in the youngest state, this differs 
from the preceding by the very broad midrib, 1-13 inch wide in 
fronds where the stipes is 3-4 lines wide; and half-an-inch wide 
in younger fronds, with stipes two lines wide. 
