186 BRITISH SEA-WEEDS. 



cimens much resemble Chondrus crispus. They differ, 

 however, in having their stems channelled, and the 

 margin of their fronds incurved. 



Genus LXXXIV. CHONDRUS. 



Frond cartilaginous, flat, forked, composed of two kinds 

 of cells; those in the centre forming a network of cyliudri- 

 cal, jointed fibres ; those of the bark necklace-like, arranged 

 vertically in gelatine. Spores minute, in confluent masses, se- 

 veral together forming a roundish nucleus, which is immersed 

 in the substance of the frond, without definite border ; tetra- 

 spores cruciate, in sori, lodged beneath the surface cells. 

 — Chondeus, from the Greek chondros, cartilage. 



This is a small genus, but is widely distributed, and 

 very abundant. 



Chondrus crispus. The curled Chondrus, 

 Carrageen, or Irish Moss. 



Frond stalked, fan-shaped, forked, flat, the segments of 

 very variable shape, from linear to broadly-cuneate. Spores 

 in oval clusters, immersed in the frond, prominent on one 

 surface, depressed on the other; tetraspores in small, red 

 sori, scattered over the frond. 



In brackish water, and in still, deep pools, this species 

 attains a very broad, luxuriant growth, and sometimes 

 becomes curled and fringed at the margin; in exposed 

 situations, it is much smaller and more narrow. It is 

 very common, but its numerous varieties are extremely 

 interesting, and may be illustrated by an extended series 

 of specimens. It is the Carrageen or Irish moss of 

 commerce, and when boiled produces a clear, tasteless 

 gelatine, which is occasionally used to make blanc- 

 mange, and as a remedy for consumption. This plant 



