_Ec._, Bark formed of an epidermis _Ep._, of a parenchyma (pulp) well developed with some oxaliferous cellules _C. o._ On the section is seen a bundle of libero-ligneous stipulaires _F. s._ _F. p._, Fibres pericycliques. _Li._, Liber, with oxaliferous cellules _C. o._ _B._, Wood. _Mo._, Pulpy pith containing cellules of ligneous dotted partitions _C. l._, and oxaliferous cellules. The cortical and medullary pulp contain in their cellules numberless grains of starch, which are not indicated in this plate. [Illustration: PLATE II. FIG. 1 FIG. 2] PLATE II. Fig. 1—TRANSVERSE SECTION OF AN AGED STEM; SECONDARY FORMATIONS. Fig. 2—LONGITUDINAL SECTION OF SAME STEM. Bark formed of a corky and pulpy cortical of a secondary origin. The primary bark exfoliates itself at a very early stage. The pulp contains some oxaliferous cellules and some grains of starch. The wood contains some veins and a considerable quantity of fibres with thick and dotted partitions. The marrow remains always pulpy and with lignified cellules. [Illustration: PLATE III. FIG. 1 FIG. 3 FIG. 4] PLATE III. Fig. 1—TRANSVERSE SECTION OF A PRIMARY ROOT. _A. p._, Heaped layer. _A. s._, Corky layer. _Ec._, Pithy bark. _End._, Endoderm; the thickening of the lateral partitions of its cellules is very apparent. _P._, Pericycle formed of a single layer of cellules. _T. c._, Conjunctive tissue or pith. _B._, Ligneous fasciculous; there are two to the diameter. _L._, Liberian fasciculous; there are two to the diameter, perpendicular to the preceding. Fig. 2—TRANSVERSE SECTION OF A ROOT; SECONDARY FORMATIONS. _L. s._, Cork, secondary. _Ec. s._, Bark, secondary; the primary formations are exfoliate. _L._, Liber. _F. l._, Ligneous fibres in large numbers and meatus. _V._, Veins of wood, dotted. _R. m._, Medullary radius. _M. s._, Pith which has become entirely sclerotic. Fig. 3—SCHEMATIC SECTION OF A YOUNG BRANCH. _Ec._, Bark. _F. f._, Foliated fasciculous not yet separated from the central cylinder. _F. s._, Fasciculous stipulaire. _Mo._, Pith. _Z. g._, Generating zone libero-ligneous. Fig. 4—GRAINS OF STARCH OF THE SEED. (Maximum dimensions: 22 to 24 p. × 15 to 18 p.) [Illustration: PLATE IV.] PLATE IV. Fig. 1—FOLIATION. TRANSVERSE SECTION OF A LEAF NOT YET UNROLLED, SHOWING THE TWO LONGITUDINAL JUTTINGS WHICH FORM THE FALSE NERVURES OF THE COCA LEAF. _F. i._, Lower surface. _F. S._, Upper surface. _N. p._, Principal nervure. _F. n._, False nervures. Fig. 2—TRANSVERSE SECTION OF ONE OF THE JUTTINGS. _E. s._, Upper epidermis. _E. i._, Lower epidermis. _F. n._, False nervure. Fig. 3—LOWER EPIDERMIS OF THE LEAF AT THE FALSE NERVURE _F. n._, WHICH IS FORMED OF LENGTHENED CELLULES WITHOUT STOMATUM _S._, STOMATUM _P._, EPIDERMIC PAPILLOUS CELLULES. Fig. 4—TRANSVERSE SECTION OF A LEAF ENTIRELY DEVELOPED.