280 



Transactions. 



covered on its ventral surface with a mat of rhizoids. In the earlier 

 stages of its development it is bright green in colour and semi-trans- 

 lucent, but later it becomes yellowish and opaque and very firm. The 



Pig. 66. — Lycopodium laterale. Young plant with fully developed protocorm and a 



very young stem -axis. X 4. 

 Fig. 67. — Lycopodium laterale. Young plant with a branched protocormous rhizome 



and" two stem-axes. X 4. 

 Pigs. 68, 69. — Lycopodium laterale. Young plant with young stem-axis and first roo^; 



just showing. 68, X 4 ; 69, X 5. 



total length of the fully developed rhizome is from 3 mm. to 5 mm., and its 

 thickness from 1 mm. to 2 mm. In one instance it was observed to have 

 forked into two equal branches, and on each of these a young stem-axis 

 was developing (fig. 67). 



Pj(j_ 7q_ — Lycopodium laterale. Transverse section of fully grown protocormous rhizome 

 before development of vascular strand, showing two protophylls above and 

 groove on ventral side. X 30. 



Pig. 72. — Lycopodium laterale. Portion of rhizome shown in fig. 71, showing relation of 

 vascular strand to the tissues of the protocormous rhizome. X 225. 



The rhizome consists of parenchj^matous tissues throughout, the cells 

 of the central region being smaller and more compact, while those nearer 

 the surface are larger and sometimes show air-spaces at their angles 

 (fig. 70). The centrally placed cells stain much darker with haema- 



