NEMALIONALES 



223 



Scinaia travels to the four auxiliary cells which have fused together 

 and there meiosis {n=io) occurs, after which one daughter nucleus 

 passes back into the carpogonium and is concerned with the 

 development of the gonimoblasts. There are, of course, no diploid 

 plants because meiosis occurs immediately after fertilization. 



Chaetangiaceae : Liagora (after one of the nereids). Fig. 146. 



The principal interest of this genus, which is very similar 

 morphologically to Scinaia, is provided by the species, Liagora 



Fig. 146. Liagora. A, carpospores of L. ■ywa'^a ( x 320). B, carpospores in fours 

 in L. tetrasporifera ( x 320). C, life cycle of L. tetrasporifera. (A, B, after Kylin; 

 C, after Svedelius.) 



tetrasporifera, an inhabitant of the Canary Islands. The carpospores 

 of this plant divide to give four spores which must probably be 

 regarded as tetraspores, and although no cytological evidence is 

 available, nevertheless it is presumed that meiosis is delayed to the 

 time when the carpospores germinate. In this species, therefore, 

 the carposporophyte is diploid, but at the same time no independent 

 tetrasporic diploid generation develops. The remaining species 

 of the genus behave like the other members of the Nemalionales, 

 although in L. viscida the carpogonial branch is five-celled instead 

 of the usual three cells. 



Gelidiaceae: Gelidium (congealed). Fig. 147. 



In this genus there is no auxiliary cell, but the presence of the 

 nutrient cells results in the production of a complex structure 



