3° 



MORPHOLOGY 



filaments, which may then 

 be spoken of as male and 

 female filaments. This 

 separation of the sexes in 

 different individuals is a 

 condition called dioecism. 

 Among these dioecious 

 forms an interesting modi- 

 fication may arise, the male 

 filaments being very much 

 dwarfed. These dwarf fila- 

 ments are produced by 

 special small zoospores, 

 which are larger than the 

 sperms but smaller than 

 the regular zoospores, and 

 are called androspores from 

 their male p'roduct. These 

 androspores swarm for a 

 time and finally settle down 

 upon female filaments or 

 even upon oogonia, where 

 they become anchored and 

 each produces a filament 

 of a few cells, whose small 



Figs. 77-79. — Oedogonium : 77, portion of a fila- 

 ment showing the large oogonium, which contains 

 an egg filled with food reserve and a single nucleus; 

 at the base of the oogonium a sperm is seen entering ; 

 also three antheridia, from two of which sperms have 

 escaped; 78, 79, young filaments developing from a 

 zoospore. — -After Coulter. 



terminal cells (anthe- 

 ridia) develop sperms 

 that are set free by the 

 opening of the caplike 

 Ud (fig. 83). 



Bulbochaete. — This well- 

 known form has the same 

 general life history as that 

 described for Oedogonium, 

 but it is a branching fila- 

 mentous form. 



Coleochaete. This is Figs. 80-82. — Oedogonium: 80, contents of oospore 



... ,. 1 escaping from the heavy wall in germination; 81, four 



a most mterestmg and ^,^^^ f<,,„i„g ;„ ^„^^^^. g, ,he four zoosp 

 a very much discussed completed. —After jueanyi. 



zoospores 



