THE THALLUS OF THE HIGHER ALGyE. 33 



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

 plasts, a special coloring matter, called phycoerylhrin. To 

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



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

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

 (conceptacle) which contains many sex-(.irgans. I'wo thirds natural size. — After 

 Luerssen. 



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

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



