326 THALLOPHYTES 
much desired by some people. The form called Irish Moss, 
shown in Figure 281, is collected in large quantities and employed 
in the manufacture of jelly, which is used directly as food and as 
the basis for the preparation of other foods. Agar-agar, which 
is used as a medium in which Bacteria and Fungi are grown, is a 
gelatinous product obtained from Red Algae. 
Nemalion. — This plant is one of the simpler forms of Red 
Algae. The plant body is a rather soft, cord-like, branching 
Cc 
Fic. 282. — Reproduction in Nemalion. A, a portion of Nemalion, bearing 
anthcridia at @ and at the right a procarp consisting of carpogonium (c) and 
trichogyne (t) to the tip of which two sperms have become attached; B, 
fertilized carpogonium beginning to develop branches on the ends of which 
the carpospores are borne; C, mature cystocarp consisting exteriorly of carpo- 
spores. XX 100-150. Redrawn with modifications from Bornet. 
structure, composed of a large number of filaments, which are 
held together by a stiff gelatinous substance. There is a central 
axis of delicate threads and an outer region consisting of short 
branches pointing outward. 
Nemalion produces both spores and gametes (Fig. 282). The 
two kinds of reproduction are intimately related, for the produc- 
tion of spores follows closely as a result of fertilization. 
The female sex organ, which is a very peculiar structure in the 
Red Algae, is called a procarp. In Nemalion the procarp is borne 
