STUDY Tf. 
ROCKWEED. Fucus. A BROWN ALGA. 
This plant grows on rocks at the seashore along the 
tide line. Its attachments or holdfasts (vhizoids) 
are not usually present in the material used. 
A. Vegetative and Reproductive Stages. 
1. 
2. 
3. 
T. 
8. 
The flattened plant body (thallus) consists of a 
midrib and the lateral expansions (wings). 
How does the branching occur ? 
The enlargements are the “air bladders.” Where 
are they situated ? 
Study an opened air bladder. What are its con- 
tents ? 
The small reproductive structures, mere specks, on 
the distal regions are the conceptacles, in which are 
borne the gamete-bearing bodies. Are the con- 
ceptacles few or many ? 
Where are they most abundant and prominent ? 
With m. observe their openings and structure. 
Make a drawing designating all parts and regions. 
B. Life Problems. 
1 
2 
3. 
4. How can it endure drying conditions during low 
Of what advantage is it in being a flattened thallus ? 
Of what importance are the air bladders ? 
What is the food of this plant ? 
tide ? 
13 
