250 



ALG^E 



organ, antherids and ' sexual 

 spores ' (oospheres), formed 

 within the sphaceles ; but 

 Janczewski believes that the 

 supposed antherozoids are in 

 reahty the zoospores of para- 

 sitic Fungi (Chytridiacese), 

 to whose attacks these sea- 

 weeds are especially liable. 

 Pringsheim describes two 

 kinds of fructification pro- 

 duced by Cladostephus, one 

 in the autumn, the other in 

 the winter ; but Wollny sug- 

 gests that both the autumnal 

 fructification and the so- 

 called unilocular sporanges 

 may be due to the attacks 

 of parasitic Chytridiacese. 

 The Sphacelariaceae have a 

 strong tendency to multiply 

 by means of buds, gemmae, 

 or propagules. Janczewski 

 describes the mature gemmae 

 as consisting of a pedicel and 



Fig. 223. — Spkacelaria cirrhosa Ag. a, natural size : 

 b^ branch with propagules, a ( x 100) ; c, filament with 

 unilocular zoosporange (x 100). (After Hauck.) 



Fig. 224.— ^S". cirrJwsa. a, filament 

 with propagule, 5 (x 140). (After 

 Reinke.) 



