394 Boodle. — Anatomy of the Ophioglosseae. 
EXPLANATION OF FIGURES IN PLATE XX. 
Illustrating Mr. Boodle’s paper on the Ophioglosseae. 
Abbreviations : — e., endodermis ; p ., parenchyma ; ph ., phloem ; s. t., sieve-tubes ; 
px., protoxylem ; developing tracheides. 
Fig. i. Ophioglossum vulgatum. Transverse section of young stele of root 
(near apex). Most of the sieve-tubes are differentiated, but only one tracheide ( px ). 
a is the position in which the second tracheide appeared in this root ; pp , position 
of the two protophloems, x 270. 
Fig. 2. Ophioglossum vulgatum. Young stele of root in a transparent prepara- 
tion ; slightly diagrammatic. The tracheides are of course not all in one plane, 
but are included in the drawing as if they were. x about 150. 
Fig* 3. Ophioglossum vulgatum. Parts of first two elements of the protoxylem 
more highly magnified to show the thickenings more accurately. The first 
tracheide is marked px at about the same point as in Fig. 2. x 375. 
Fig. 4. Ophioglossum pendulum. Transverse section of stele of rootlet within 
the cortex of the parent-root, showing monarch structure. x 135. 
Fig. 5. Ophioglossum pendulum. Stele of same rootlet when free, showing 
diarch structure, x 130. 
Fig. 6. Botrychium Lunaria. Base of rootlet showing monarch structuie. 
x 275. 
Fig. 7. Botrychium Lunaria. Same rootlet becoming diarch, x 275. 
Fig. 8. Ophioglossum vulgatum. Stele of root in cortex of stem, showing 
change of orientation, x 88. 
Fig. 9. Ophioglossum vulgatum. Transverse section of root, showing five partly 
lignified developing tracheides ( t ). x 130. 
Fig. 10. Ophioglossum vulgatum. Part of transverse section of root more 
highly magnified, showing one developing tracheide with its protoplasmic contents. 
x 365. 
Fig. 11. Ophioglossum vulgatum. Longitudinal section of root, with nucleus 
( n ) and protoplasm in the developing tracheide on the left, x 375. 
Fig. 12. Ophioglossum vulgatum. Transverse section of one bundle of petiole, 
x 130. 
Fig. 13. Ophioglossum vulgatum. Part of one vascular bundle of the stem cut 
transversely, with five developing tracheides. x 130. 
Fig. 14. Botrychium Lunaria. Transverse section of stele of root-base in the 
cortex of the stem, showing secondary thickening, x 195. 
