1913] YAMANOUCHI—ZANARDINIA 5 
in their middle region produce male or female gametangia, indicat- 
ing that the latter are hairs in origin. 
The mature male gametangium consists of a number of tiers of 
small cells (the male gamete mother cells), each tier comprising 8 
cells, and since there are at most 33 tiers (fig. 4, 6), the output of a 
single male gametangium is about 264 gametes. The mature male 

Fic. 2.—Portions of thallus with a number of filaments bearing both male and 
female gametangia: a, male and female gametangia with stalks composed of one or 
two cells; most of them are near maturity; 6, young gametangia; a female game- 
tangium with a stalk of three cells. 
gamete in the free swimming condition outside the gametangium is 
oval and usually contains two plastids. A portion of one of the 
plastids lying laterally near the anterior end has a deep orange 
color, which is the red pigment, and in close association with this 
pigment are two cilia, one directed toward the anterior end, 6 
times the length of the gamete, and the other in the opposite 
