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small quadrate cells with dense chroma- 

 tophores. The outer cortex, comprising 

 those layers underneath the epidermis 

 of similar appearance with it, is distin- 

 guished from the inner cortex by the 

 much larger cells and less copious con- 

 tents of the latter. The inner cells of 

 the inner cortex are often somewhat 

 peculiar. Thus, in Nereocystis they are 

 extended into thermometer-tube-like 

 sieve tubes. Cells of this character 

 are also found in Macrocystts. In 

 Pterygophora the innermost cortical cells 

 are sclerenchymatous. The pith is 

 composed of a web of loosely anasto- 

 mosing filaments embedded in gelatine. 

 In bulbs of Nereocystis, in which the 

 cavity is produced by the distension of 

 the upper part of the stipe, with des- 

 truction of the pith, remnants of the 

 pith may often be found, looking like 

 cobwebs stretched over the inner wall 



