434 BOTANICAL GAZETTE [may 



masses 



mass between, but followed up for nearly an inch, it never be- 

 comes triarch. The xylem becomes horseshoe- or ring-shaped, 

 much as in figs. 17 and 19, changing constantly, and there is no 

 hint as to how the multiprotoxylic condition of the adult stem 

 arises. The irregularity and continual change in the xylem of 

 these young stems are comparable to the conditions described by 

 Miss Wiggles worth (12) in young Lyco podium sporophytes 

 growing from gametophytes. 



Hegelmaier's statement that the bulbils replace leaves in the 

 phyllotaxy is confirmed by an examination of the relation of bulbil 

 and leaf traces. On following these back in cross-sections to their 

 junctions with the xylem strands of the central cylinder, the 

 bulbil traces are found in close succession. In many cases they 

 represent successive leaves; in other cases a leaf trace stands be- 



examined 



traces all fell within a single leaf spiral. 



Conclusions 



the 



a simple vascular strand with mesarch concentric arrangement; 

 whereas branches have a vascular system with complex exarch 

 radial arrangement. Furthermore, it is not a reduced dichotomy 

 or the equivalent of the bulblets of Lilium or Allium. 



2. It is not the homologue of a sporangium, for the reason, 

 among others, that it receives a prominent vascular strand, a 

 feature which is lacking in the sporangia of all Lycopodiales. 



retainin 



in 



homolo 



may 



history of the leaf bearing it that the latter exhibits the leaf 

 character only while inside the cortex of the stem. 



Further observations on the bulbils and habits of L. lucidulum 



In the literature of the subject, I do not find any recognition of 

 the periodicity of the bulbils. In L. lucidulum they are quite as 

 responsive to season as the sporangia. The latter begin to form 



