364 THE SEA SHOES 



when young, and only a gelatinous fluid when the plant is mature. 

 The spores exist in rounded clusters among the cells of the tube, 

 and the tetraspores are similarly situated. A variety with wide 

 wavy fronds is sometimes found in the brackish water near the 

 mouths of rivers. 



GloiosipTionia capillaris is a very delicate and beautiful weed 

 found in the lowest tide pools of the south coast. Its frond is a 

 very slender branched tube, filled with a gelatinous fluid, and con- 

 posed of delicate filaments embedded in transparent gelatine. It 

 is a beautiful object for the microscope. 



ScMzymenia (Iridcea) edulis has flat, oval, dark-red fronds 

 that grow in clusters ; and, being eaten by various marine animals, 

 is often found imperfect and full of holes. The fronds are some- 

 times a foot or more in length, and five or six inches wide. They 

 are thick and leathery, and each is supported on a short, cylin- 

 drical stem. 



In the lower tide pools we commonly meet with Furcellaria 

 fastigiata, with brownish-red, cylindrical fronds, solid, forked, and 

 densely tufted. The branches are all of the same height, with 

 sharp tips ; and the spore-clusters are contained in terminal 

 lanceolate pods. This weed is very much like Polyides, of another 

 order, but may be distinguished by its fibrous, creeping root, while 

 that of Polyides is a disc. 



The genus Chylocladia is characterised by a tubular rounded 

 frond composed of two layers, the inner consisting of branching 

 filaments, and the outer cellular. The spores are contained in 

 external cones with a pore at the apex, and the tetraspores are 

 among the superficial cells of the branches. There are two 

 common British species of the genus, one of them C.articulata 

 with long, tubular fronds, constricted at intervals, the lower 

 branches forked and the upper whorled and tufted ; and Cf. 

 clavellosa, with freely branched fronds bearing short spindle- 

 shaped branchlets. 



One of the best-known algae of the present family is the Irish 

 Moss or Carrageen (Chondrus crispus), which will be at once 

 recognised by its representation on Plate VIII. Its fronds are 

 cartilaginous, forked and fan-shaped ; and, when growing in deep, 

 sheltered pools, its branches are often broad and much curled. 

 This weed is an important article of commerce, being still used as 

 a food for invalids. When boiled it yields a colourless gelatine. 



In the genus Gigartina the frond is cartilaginous, flat, or thread- 



