THALLOPHYTA 327 
plants (Fig. 332).° When the an- 
theridia are formed in ordinary fila- 
ments, they usually occur as rows 
of small cells, each of which pro- 
duces two spermatozoids. Dwarf 
male plants are developed from spe- 
cial spores known as androspores, 
which are very much like the zo6- 
spores but are formed in rows of 
small cells (Fig. 334). These an- 
drospores attach themselves on or 
near the odgonia, and each grows 
into a dwarf male which consists of 
aa i only one or a few cells. 
\ \ it t/, Relationship. Oedogonium shows 
Wy a very high degree of sexual dif- 
S ferentiation, as fusion takes place 

Fi1g.334. Escape of androspores 
of Oedogonium 
Redrawn after Hirn 
\ \f 
NAN 
\ 
\ 


Wy Ip 
\ \ ¥ y ? } 



Ergedso. Chara 
Left, portion of a plant; right, section through apex of a long branch, showing 
a single-celled growing point 
between highly specialized eggs and spermatozoids. In this re- 
spect it is much more advanced than U lothrix, where fusion is 
between two ciliated gametes. Owing to the fact that the 
