294 THE SEA-WEEDS AT HOME AND ABROAD. 
membranous. It is usually found in shallow pools, but 
where the plant is never left to even temporarily become 
dry. Though very eommon on the Atlantic shores of 
Europe it does not seem to have been recognized here as 
growing on this side of the ocean. The Cystoseira, too, is 
only recognized as American in a California species though 
several are known to the British waters, and the Phyllospora 
Menziesii, detected by Menzies himself when with Vancouver, 
has elsewhere as yet only occurred in the deeper soundings 
of the California coast. In this plant we see the same glob- 
ular air vessels we have noticed in the fuci. To this family 
belong also the gulf weeds, Sargassum, a vast genus and of 
which some species extend as near as Nantucket and Provi- 
dence. One of them, the tropical Sea-grape (S. bacciferum), 
is seen floating in masses in the gulf stream, and is a familiar 
object. Kützing gives us a list of one hundred and three 
distinct species known over the globe ! 
An excessively branched and bushy mass of dark brown 
fibres, covered with short harmless prickles, and sometimes 
growing several feet in length, often presents itself on the 
sandy beaches, evidently torn from the bottom of deep 
water. This is Desmarestia aculeata, so variable in appear- 
ance at different stages of growth as to have led good bota- 
nists astray. When young, this otherwise stiff, bristly weed 
is clothed with the most delicate pencils of finely divided 
. filaments, of a beautiful green color, a condition worth seek- 
ing. Its mode of bearing seeds is unknown. 
Another natural order of the Melanosperms, comprising a 
great variety of kinds, is the Laminariacee, among which — 
from a simple cylindrical threadlike frond of the diameter of 
a whip-cord, and often twenty, thirty or forty feet in length, 
tapering at the extremity, and fixed at the base by a disk 
(Chorda filum) to a frond of broad dimensions, and sup- 
ported by a long stalk (Laminaria or oar-weed) — we find a 
series of modified forms in species found in our waters. Of 
the sea leaf ( Thallasiophyllum), one of this order, a writer 
