HoLLOWAY. — SUidies in the Neiv Zealand Species of Lycopodium. 265 



L. laterale. 



This prothallus (text figs. 13-16, and Plate XVIl, fig. 3) corresponds, 

 with certain secondaiy differences, to the type of L. ctrnuum. All the pro- 

 thalli found were colourless, except for a very faint tinge of green in the 

 lobes. They are about 1 mm. in length. There is a lower rounded portion 

 (" primary tubercle ") darker in appearance than the rest of the pro- 

 thallus, and which in the solid stains more deeply with haematoxylin. 

 Examination of serial sections showed that the cells of this region were 

 occupied by a fungus. This lower part of the prothallus bears numerous 

 long rhizoids. The middle region of the prothallus ("shaft") in two 

 cases was very short, giving the prothallus a stout and solid and opaque 

 appearance (fig. 14). In the other prothalli it was slightly longer, these 

 appearing more cylindrical and drawn out. Tlie leafy expansions on 

 the crown of the prothallus are fi.lamentous and less lobe-like than in 

 L. cernuum. A characteristic feature of all the prothalli of L. laterale 



Figs. 13-16. — Lycopodium laterale. 



13, X 20 ; 



Complete prothalli, with young plants attached. 

 14, X 10 ; 15 and 16, X 14. 



examined was the presence of a filamentous outgrowth or a group of 

 outgrowths on the shaft, either lower down towards the tubercle or 

 higher up beneath the crown. None of the prothalli of L. cernuum 

 seen by me showed any such leafy expansions on the shaft. Two pro- 

 thalli, one of which is shown in fig. 16, possessed a long process attached 

 to the primary tubercle. The end of this process was club-shaped, and 

 consisted of numerous cells, but the remainder was thinner, and showed 

 two or three roAvs of longish cells. Goebel (10, p. 194) quotes from 

 Treub that in L. salakense, and occasionally also in L. cernuum, several 

 branches may arise from the primary tubercle. Perhaps the process 

 found in the two prothalli of L. laterale is of the nature of such 

 a branch. It is interesting, however, to compare this with the long- 



