Phylloglossum Drummondii , Kunze . 
33i 
VIII. Summary. 
I. That the tuber of Phylloglossum is, in fertile plants, a modified 
branch is supported by the following facts : 
1. A gap is left in the stele of the main axis by the exit of the vascular 
strand of the tuber. 
2. The stele of the tuber often shows a corresponding gap. 
3. The tuber bears leaves, some of which are considerably reduced. 
II. In general, sterile plants consist of a simple axis, the apex of which 
has formed a storage tuber. It is possible that, in the larger specimens, 
branching occurs as in fertile plants, but the arm, which in the latter 
produces a cone, is in sterile plants arrested early in development. 
III. The tuber of Phylloglossum can no longer be compared with the 
protocorm of Lycopodium cernuum , but the two genera are brought nearer 
together, since Phylloglossum has proved to be not characteristically an 
unbranched form. 
In conclusion, I wish to thank Professor Benson for suggesting this 
work, and for her helpful criticism during the course of the investigation. 
