THE THALLUS OF THE HIGHER ALGjE. 



33 



algae, there exists, in addition to the green of the chloro- 

 plasts, a special coloring matter, called phycoerythrin. To 

 the naked eye, this color overpowers the green and gives the 



Fig. 42. — Upper part of a plant of Fucus vesiculosus. r, midrib of thallus ; /, 

 bladders; s, swollen tips covered by numerous elevations, in each of which is a pit 

 (conceptacle) which contains many sex-organs. Two thirds natural size. — After 

 Luerssen. 



plant a pink tinge. In other red algae it is often present in 

 greater quantity and variety of hue, so that brilliant reds and 



