RED ALGAE (RHODOPHYCEAE) 325 
Algae, the plant body is commonly differentiated into parts 
similar in form, although not in structure, to the roots, stems, 
and leaves of the higher plants. The cells are commonly ar- 
ranged in such definite lines that the plant body has the appear- 
ance of a bundle of closely joined simple filaments. The evident 
protoplasmic connections between cells and the gelatinization of 
cell walls are other notable features. 
Fic. 281.— Irish Moss, Chondrus crispus, much used for food. Natural size. 
The life history of some of them is quite complex. They have 
spores, but their spores and likewise their gametes have no cilia, 
a curious feature since these plants are wholly aquatic. The 
female sex organ is multicellular and more complex than the sex 
organs of the Brown Algae. 
Several forms of the Red Algae are of economic importance. 
Some are used as food, being dried and kept for long periods 
The gelatinous material obtained from Red Algae forms a delicacy 
