232 INTRODUCTION TO BOTANY 
portions of this country the farmers collect and carry inland 
great quantities of brown alge and spread them over the 
cultivated land as a fertilizer.t 
Fig. 181. A red alga (Dasya) 
219. The red alge. The red algze grow mostly in deeper 
water than do the brown alge. They are almost wholly con- 
fined to salt water. 
The marine forms of this group present most striking shapes 
and colors. They are of different shades of red, varying from 
the most brilliant to those that are dark and somber, while 
1 For the reproduction of the brown and red alge, see Bergen and Davis, 
Principles of Botany. 
