506 Gwynne- Vaughan . — On some Climbing 
parenchyma and the phloem on the adaxial side of the xylem of the 
primary branch encroach on it so as to form a sinus which eventually 
reaches the protoxylem (Text-fig. 7, C 3 ; Plate XIV, Photo 8). The proto- 
xylem thus becomes endarch, the xylem now having the form of a C ; this 
remains open through subsequent branchings (Text-fig. 7, D). When the 
trace to a secondary branch is given off, a small xylem strand departs from 
the end of the arm of the C, and is supplied successively with two proto- 
xylems (Text-fig. 7, C 1-3 ; Plate XIV, Photo 7). The trace of a secondary 
branch never obtains a dorsal protoxylem (Text-fig. 7, E 1 ), and the trace 
to a branch of the next higher order has only one adaxial protoxylem 
(Text-fig. 7, E 2 ). 
Summary. 
[1. Bertrand and Cornaille's interpretation of the petiolar trace of 
Lygodium , as derived by the union of the inverse folds of the metaxylem 
of a C-shaped trace, is confirmed. 
2. In Lygodium japonicum the dorsal protoxylem of the petiolar 
trace, consisting of annular or spiral elements, is not exarch but mesarch, 
being more or less completely enclosed by centrifugal metaxylem. 
3. In the petiolar trace and branch-traces of Davallia fumarioides all 
stages between the open C-shaped trace and the condition present in 
Lygodium are found. 
4. In this condensation of the C-shaped trace of Davallia fumarioides 
the adaxial hooks of xylem completely disappear. It may be inferred 
that they are absent in the trace of Lygodium also.] 
DESCRIPTION OF THE FIGURES IN PLATE XIV. 
Illustrating Professor Gwynne* Vaughan’s paper on Some Climbing Davallias and the Petiole 
of Lygodium. 
(All these figures are from untouched photographs.) 
Photo 1. Transverse section of the petiolar trace of Davallia fumarioides four inches below the 
first branches ; cf. Text-fig. 7, A 2 . Slide No. 2148. (x 46.) 
Photo 2. Transverse section of the petiolar trace of a strong leaf of Davallia fumarioides just 
preparing for the departure of the trace to the first primary branch on the left ; cf. Text-fig. 8, A. 
Slide No. 2149. (x 46.) 
Photo 3. Section of the same petiolar trace with the trace to the first primary branch just 
separated on the left ; cf. Text-fig. 8, A. Slide No. 2149. (x 46.) 
Photos 4, 5. Transverse section of the petiolar trace of a weaker leaf of Davallia fumarioides 
just below the separation of the trace to one of the second lowest pair of primary branches and 
during the separation of the xylem of the trace ; cf. Text-fig. 8, B. Slide No. 2160. ( x 46.) 
Photo 6. Transverse section of the trace of a primary branch of Davallia fumarioides near the 
base of the branch ; cf. Text-fig. 7, B, Slide No. 2154. ( x 67.) 
