i 9 4 
PHARMACEUTICAL BOTANY 
goes a resting stage and upon the advent of favorable conditions 
develops into a new Ectocarpiis filament. 
Fucus Vesiculosus (The Bladder Wrack) . — This form, a brown 
alga, occurs as a flat thallus, which forks repeatedly, a type of 
branching called dichotomous. It grows near the surface of sea 
water, attached to rocks by means of a basal disc-shaped holdfast. 
In the upper branches of the thallus are to be found air bladders 
which are more or less spherical and usually in pairs. The tips of 
old branches become swollen and are termed receptacles. They 
are dotted over with minute cavities called conceptacles. Within 
these conceptacles the antheridia, or male sexual organs, and the 
archegonia , or female sexual organs, are produced. The conceptacles 
also contain numerous branching filaments called paraphyses, which 
arise from the cells lining the cavities. The antheridia are found as 
outgrowths of these paraphyses and produce sperms or male sexual 
cells. The oogonium is a large, globular, stalked cell and produces 
eight eggs, each of which is a female sexual cell. The eggs and sperm 
escape into the sea water. The eggs float and are surrounded 
by myriads of sperms. One sperm, only, gains an entrance, after 
which its nucleus fuses with that of the egg to form an oospore. 
The oospore at once develops into a new Fucus plant. 
Class III. — Rhodophyce^e, the Red Alg,e 
A greatly diversified group comprising the majority of marine algae 
but represented also by some fresh-water forms. The marine red 
algae are generally found at or just beyond the low water mark. 
Their vegetative bodies vary from simple branching filaments 
through all gradations to forms differentiated into branching stems, 
holdfasts and leaves. It has been observed that many of the higher 
types are composed of numerous filaments which are arranged so 
closely and connected so intimately by protoplasmic processes 
as to resemble the tissues of plants higher up. Their color may be 
red, purple, violet, or reddish-brown or even green and is due to the 
presence of phycoerythrin, a red pigment, which is found in the 
chromatophores with but frequently masking the chlorophyll. 
Chondrus crispus and Gigartina mamillosa yield the official drug 
