207 
from the Lower Coal Measures of England. 
represent an incipient phase in the formation of primary transfusion tissue. 
The palisade is but little differentiated, and the leaf parenchyma is but 
slightly lacunar even on the abaxial surface of the leaf, which is stomatiferous 
except at the base. 
The whole leaf has a markedly xerophilous character, and shows in its 
upper part a considerable resemblance to the type named C. Wedekindi by 
Felix, while in the basal parts it more resembles the types called C. locu- 
losus and C. robustus by the same author. 
EXPLANATION OF PLATE XXII. 
Illustrating Dr. Margaret Benson’s paper on Cordaites Felicis. 
The following abbreviations are used : — H = hypodermal strand of fibres between bundle and 
partition ; Is = inner and Os = outer sheath of bundle ; L = lacunae of leaf ; P = phloem ; Pa — 
partition ; x = centrifugal xylem. x' = centripetal xylem. 
All the slides come from the R. H. C. Collection. The micrographs, with the exception of 
Fig. ii, were taken and the sections cut by C. H. Wells, the Botanical Laboratory attendant. 
Fig. i. Transverse section, probably in the upper part of the lamina, under a low magnification 
to show distribution of bundles and sclerenchyma. C. N., 365. 1. x 20. 
Fig. 2. Transverse section, probably in the basal part of the lamina, under a low magnification 
to show distinctive character. C. N., 365. 2. x 20. 
Fig. 3. Horizontal longitudinal section in the upper part of the lamina. The plane of section 
is about equidistant from each surface. The cells of the leaf parenchyma are collapsed and the 
lacunae between the strands are therefore exaggerated. C. N., 368. 2. x 20. 
Fig. 4. Longitudinal section vertical to the surfaces in plane between the bundle and the 
partition. The minute size of the lacunae is shown well. The palisade is to the right of the figure. 
C. N., 365. 10. x 95. 
Fig. 5. Transverse section in thicker part, to show weak development of bundle sheath and 
corresponding increase in strength of partition. This figure should be compared with the low-power 
photograph shown in Fig. 2, and with Felix’s figure of C. robustus , to which reference is made 
in the text. C. N., 365. 8. x 95. 
Fig. 6. A single bundle from a section in the basal part of the leaf. There is much centrifugal 
wood and division of the bundle is proceeding. C. N., 365. 19. X 95. 
Fig. 7. Transverse section through a somewhat thicker part of a leaf, showing both centri- 
fugal xylem and inner sheath. The compact nature of the leaf parenchyma is shown. C. N,, 
365. 12. x 95. 
Fig. 8. Transverse section of a bundle in the upper part of the leaf, showing inner sheath but 
otherwise no centrifugal xylem. C. N., 365. 3. x 95. 
Fig. 9. A transverse section showing incipient division of a bundle -\yhich sometimes occurs 
in the middle portion of the lamina. Divisions in this plane are carried out in bundles which have 
a normal sheath. C. N., 365. 4. x 95. 
Fig. 10. Transverse section showing inner sheath and phloem. The hypodermal mass (H) 
intervening between the partitions (Pa) and the bundle strand is indicated ; also the position of 
stomates is indicated on either side of the bundle strand. C. N., 365. 5. x 95. 
Fig. 11. Photograph of transverse section from the same leaf as the text-figure is taken from. 
P = phloem, x = centrifugal xylem, and Is = inner sheath. C. N., 72. 1. x 225. 
