SECTIONS OF BARK. 
PLATE I. 
Fig. 1. C. succirubra , from Ceylon, grown in the forest 
under dense shade . — a, the suberous coat; b , cells be- 
coming changed into cork ; c, prolongation of the me- 
dullary rays; d , laticiferous vessels;. /, liber-fibre, cut 
transversely; g , fibre not yet filled up with layers of 
incrusting-matter ; h, indications of the cambium layer. 
X 50 diameters. 
Fig. 2. C. succirubra, from Ceylon, grown in open 
garden . — a , the suberous coat ; b , cells compressed and 
undergoing change ; c , the prolonged medullary rays 
opening out into cellular tissue of ordinary structure ; 
d , laticiferous vessels ; e , cellular tissue of the liber in 
smaller polygonal, or globular cells; /, fibres of the 
liber; h, point of junction with the wood, forming a 
cinnamon-coloured inner surface of the dried bark ; i , 
crystals of alkaloid. X 100 diameters. 
Fig. 2 a. Portions of cellular tissue of the above, 
showing more distinctly the crystals above mentioned ; 
i, crystals, probably of cinchonidine ; j, small globular 
aggregations, probably of alkaloid, united with cerotic 
acid. X 100 diameters. 
Fig. 2 b. The same crystals as above. X 200 dia- 
meters. 
Fig. 5. C. succirubra , from Ceylon, grown in the open 
garden , six feet apart. — a , the suberous, d , the latici- 
ferous vessels ; e, liber-fibres of larger dimension ; h , 
dark brown inner surface ; i, crystals of alkaloid. X 50 
diameters. 
Fig. 5 a. Portion of cellular tissue of the above ; i, 
crystals, probably of cinchonidine ; j, globular concre- 
tions; k, isolated crystal; /, abnormal formation, a cell 
filled with granulations of some earthy compound (in- 
soluble in any menstruum employed), also colouring- 
matter. X 100 diameters. 
Fig. 5 b. Groups of the above crystals, and also iso- 
lated crystals. X 200 diameters. 
Fig. 8. G. succirubra , original bark, six months under 
moss. — a , the suberous coat ; i, crystals, probably of 
kinovate of quinine; l , abnormal concretions; d , lati- 
ciferous vessel ; f fibres of the liber ; e , lax cellular 
tissue ; h , internal surface, with indications of the cam- 
bium. X 50 diameters. 
Fig. 8 a. — i, groups of crystals, as above ; Z, abnormal 
concretion. X 100 diameters. 
PLATE II. 
Fig. 1. C. succirubra , bark in an early stage of re- 
newal , from Ootacamund. — a , the suberous coat; c, cel- 
lular tissue, which apparently marks the course of the 
circulation from the medullary rays to the external 
coat; /, isolated liber-fibre (two seen in juxtaposition 
on the reverse side) ; Z, abnormal concretions ; e, lax 
cellular structure (favourable to the production of qui- 
nine) ; h , indication of cambium. X 50 diameters. 
Fig. 2. C . succirubra, first crop of renevoed bark, from 
Ootacamund. — a, thick, suberous coat ; b, layer of cells, 
filled with resinous deposit ; m, cellular envelope of cell- 
structure, resembling specimen (Plate II. Fig. 2, c Qui- 
nologia ’) ; d, large laticiferous duct ; c, cells of normal 
structure, forming continuation of the parenchyma of 
the medullary rays ; e, liber-fibres, normal in character 
and position ; g, young liber-fibres not filled up ; li, hard 
inner surface. X 50 diameters. 
Fig. 3. C. succirubra, second crop of renewed bark . — 
a, the suberous coat ; b, cellular structure, apparently 
gorged with resin, and changing into cork ; n, spiral or 
reticulate vessels ; m, normal structure of the cellular 
envelope ; e, lax cellular structure, in places filled with 
cincho-tannic acid in an early stage of oxidation ; c, 
course of the prolongation of a medullary ray ; f, nor- 
mal liber-fibres; h, hard and coloured inner bark. 
X 50 diameters. 
Fig. 4. Spiral and reticulate vessels from the above 
at n, simply spiral vessels. X 100 diameters. 
Fig. 5. Spiral and reticulate vessels (from a trans- 
verse section of the above Fig. 3) ; m, the cellular tissue 
coloured by resin ; n, the ends of reticulate vessels ; o, 
vessels of the cellular tissue, apparently emptied of their 
colouring-matters by contact with the spiral vessels. 
X 100 diameters. 
Fig. 6. Natural size of section, at n showing the po- 
sition of the spiral vessels. 
Fig. 7. C. succirubra, second crop of renewed bark (long, 
sect.) — a, the suberous layer ; m, cellular tissue ; d, the 
same, surrounding laticiferous duct; e, cells of paren- 
chyma, gorged with colouring-matter ; f, fibres of the 
liber. X 50 diameters. 
Fig. 8. C. succirubra, second crop of renewed bark (pro- 
bably exposed to greater heat). — a, the suberous coat ; 
b, current of colouring and probably resinous matter 
from the medullary rays to the bark ; c, lax cellular 
tissue ; i, crystals of alkaloid ; d, laticiferous ducts ; e, 
globular cells of parenchyma, filled with colouring- 
matter ; Z, abnormal concretions ; f, fibres of the liber ; 
h, internal surface, with trace of cambium. X 50 dia- 
meters. 
Fig. 8 a. Crystals of alkaloid, seen in the parenchyma 
of the above. X 100 diameters. 
Fig. 10. Fibres of the liber, probably from C. Palton 
(see p. 23). X 50 diameters. 
c 
