I. 



1917] CHAMBERLAIN— LYCOPODIUM 59 



y fungus. Whether it has a protocorm stage is not known. Treub 



j failed to find sporelings when he made his first investigation; later, 



in his work on the embryogeny of L. cernuum, he figures a proto- 

 corm stage in L. salakense. 



It is interesting to note that the protocorm stage has been found 

 only in L. cernuum, L. salakense, L. inundatum, and L. later ale, all 

 of which have spores which germinate, giving rise to green short- 

 lived prothallia. The spore-bearing plants of all 3 species, as well 

 as that of L. salakense, grow upon the ground. No green prothal- 

 lium or a protocorm phase in the embryogeny has yet been 

 reported for any epiphytic Lyco podium. 



L. volubile. — The only reference to the prothallium of this 

 species is by Holloway (16). He says "the prothallus is large, 

 firm, and long-lived. Healthy prothalli were seen still attached to 

 sporelings which were as much as 10 cm. in length. Generally the 

 prothalli are subterranean, being buried 1-4 cm. in depth; in several 

 instances, however, they were observed growing on the surface of 

 the ground, and the upper portion of the prothallus was then well 

 supplied with chlorophyll." 



The material at my disposal included 9 prothallia and 2 spore- 

 lings, one of them still attached to the prothallium (figs. 4-9). All 

 belong to the subterranean tuberous type, and 4 of them (figs. 4, 

 5, 8, and 9) show a primary tubercle. Although the material is 

 somewhat limited, it is evident that there is considerable variation 

 in size and form. 



The endophytic fungus is most abundant midway between the 

 center and the surface, and is entirely lacking in the crown, in the 

 upper part of the depression within the crown, and in the axis of 

 the prothallium. Cells with considerable fungus abut directly 

 upon those with none at all, making a sharp contrast (fig 12). A 

 detail is shown in fig. 13. 



The crown is differentiated into two regions in some places, only 

 the inner one of which bears archegonia and antheridia, as shown 

 in figs. 5 and 6 ; but even in these 2 prothallia some portions of the 

 crown show no such differentiation, and the prothallia shown in 

 figs. 7 and 8 have uniformly rounded crowns with no indication of 

 two regions. While most of the sex organs are on the swollen rim 





