THE HALF-TIDE POOL. 69 



by a clear membrane, forming a distinct cell, and each 

 of these is immersed in an oblong body seated on a 

 main stem. 



This curious little plant much resembles the Cactus 

 Opuntia, and may be confounded with another seaweed 

 — Chylocladia Articulata ; but this latter is of brighter 

 colour, grows larger and in denser tufts, the internal 

 structure and fruit quite different. 



HALIDETS. 



Generic character. — Frond compressed, branched, 

 bearing oblong air vessels on stalks resembling pods. 



Fructification. — Oblong, stalked pods, containing 

 both spores and antheridia. 



This plant ranges from high to low tide. It varies, 

 like all who do so, from short bushy tufts to floating 

 fronds, sometimes four feet long. The colour is olive. 

 It is attached to the rock by an expanded disc, so 

 firmly that a man's strong pull will hardly wrench it 

 away, and it is a little world in itself when growing 

 near low- water mark, very productive to the naturalist 

 who learns more than seaweeds. 



"Look who list, thy gazeful eyes to feed 



With si^ht of that is fair ; look on the frame 



Of this wide universe, and therein read 

 The endless kinds of creatures, which by name 

 Thou canst not count, much less their nature's aim ; 



All which are made with wondrous wise respect, 



And all with admirable beauty deckt." 



Halidets Siliqtjosa. — So look on this long brown 

 weed, and examine first — itself. Those swollen pods 

 are air chambers, divided into ten or twelve cells, 



