90 THE HISTORY OF CREATION. 



forms belong to this group. Especially I may mention 

 here the stately sugar- tangle (Laminaria), whose slimy, olive 

 green thallus-body, resembling gigantic leaves of from 10 

 to 15 feet in length, and from a half to one foot in breadth, 

 are thrown wp in great masses on the coasts of the North 

 and Baltic seas. 



To this class belongs also the bladder-wrack (Fucus 

 vesiculosus) common in our seas, whose fork-shaped, 

 deeply-cut leaves are kept floating on the water by 

 numerous air bladders (as is the case, too, with many 

 other brown Algfe). The freely floating Sargasso Alga 

 (Sargasso bacciferum), which forms the meadows or forests 

 of the Sargasso Sea, also belongs to this class. 



Although each individual of these large alga-trees is 

 composed of many millions of cells, yet at the beginning 

 of its existence it consists, like all higher plants, of a single 

 cell — a simple egg. This egg — for example, in the case of 

 our common bladder- wrack — is a naked, uncovered cell, and 

 as such is so like the naked egg-cells of lower marine 

 animals — for example, those of the Medusae — that they 

 might easily be mistaken one for another (Fig. 19). 



Fig. 19. — The egg of the common bladder- 

 wrack (Fucus vesiculosus), a simple naked 

 cell, much enlarged. In the centre of the 

 naked globule of protoplasm the bright kernel 

 is visible. 



It was probably the Fucoideae, or 

 Brown Algae, which during the pri- 

 mordial period, to a great extent, 

 constituted the characteristic alga-forests of that immense 

 space of time. Their petrified remains, especially those of 



