SPHAEROPLEA. 103 



BULBOCHAETE RHADINOSPORA, Wittr. 



Oogonia oblong-ellipsoid, patent, beneath the andro- 

 sporangia or the terminal setae ; androsporangia epigynous ; 

 dwarf males near to or seated on the oogonia. 



Diameter veg. cells, 10-13 /* (Wittr. 15-21); U -2 times 



longer. 



Diameter oogon., 29-35 //by 50-56 /* (Wittr. 64-80 /*). 

 Diameter androsp. cells, 13-15 ^ by 16-23 yw. 

 Diameter dwarf males, 14-16 // by 23-25 //. 

 Diameter sperm, cells, 8 /* by 6-7 yw. 



Specimens from Florida. 

 Plate LXXXIX, figs. 4, 5. 



Family VILSPHAEROPLEACE^l. 



Filamentous, green, branchless and rootless ; denizens of water 

 and of the air ; propagation in a manner sexual. The oogonia 

 are formed by a spherical massing of the chlorophyl of a cell of 

 a filament into one or many oospheres. In other filaments the 

 chlorophyl separates into small bodies which change color from 

 green to red, or yellowish red, producing spermatozoids ; these 

 escape through fissures in the walls, find their way to the oos- 

 pheres and fructify them ; when impregnated they also change 

 color to red or reddish yellow ; a thick membrane is formed 

 around them ; now resting spores, they lie dormant a long time 

 before they germinate. 



Genus 12, SPHAEROPLEA, Ag. 



Filamentous, green, composed of long cells in which the 

 chlorophylous contents are so distributed as to produce large 

 vacuoles at regular intervals, each surrounded by annular bands 

 enclosing 3 to 7 starch grains. All the vegetative cells develop 

 sexual organs. The oospheres are green and numerous in a 

 mother cell ; after fertilization these become oospores clothed 

 with 2 or 3 membranous envelopes ; color changes from green to 

 red. The exterior hyaline membrane is loose and beautifully 

 plaited. The spermatozoids are developed in large numbers in 

 separate cells ; they are club-shaped with two cilise at the thinner 

 end, color red. They pass out through fissures, enter the cells 

 of the oospheres through pores in the wall of the cells, and 

 fructifv them. 



