HoLLOWAT. — Studies in the New Zealand Species of Lycopodium. 199 



of epidermal cells. This lateral process was free of the fungus, except in 

 certain isolated subepidermal cells which lay at the bases of the young 

 rhizoids. From this latter fact it is apparent that, at ^ny rate when the 

 extension in length of a branch is rapid, infection may take place from 

 without through the rhizoids, and that the distribution of fungus throughout 

 the prothallus does not take place simply through its forward extension 

 from the older regions. The original apex of the oldest conical region 



Fig. 9. — L. Billardieri var. gracile. A young prothallus complete, in general view. 



X 60. 

 Fig. 10. — L. Billardieri var. gracile. Longitudinal section of the basal cone of the 



prothallus illustrated in fig. 1, sho^ving remains of spore on the first-formed 



cell. X 170. 

 Fig. 11. — L. Billardieri var. gracile. Longitudinal section of central body of mature 



prothallus, showing general arrangement of tissues, and also foot of young 



plant. X 47. 



was intact, and the first-formed cells were clearly to be traced. Most of 

 the mature prothalli of these epiphytic species which I found were incom- 

 plete in their basal region, probably on account of the decaying-away of 

 these oldest tissues through age ; but I also found several mature prothalli 

 both of L. Billardieri and of the variety gracile in which the original 

 end was intact. This was the case with that shown in fig. 1, A highly 



