668 
Worsdell. — A Study of the Vascular System in 
recent of the vascular structures in this order ; neither stipules nor sheathing 
leaf- base occur (Figs. 31 and 32). In the structure of the petiole the 
Ulicieae or Winteraceae section of this order shows a certain resemblance 
to Calycanthaceae, but owing to the absence of any cortical system of 
bundles they are much more modified and advanced than this latter group. 
I need not here occupy space with a description of the remaining 
genera, as they exhibit nothing of special interest. 
Bibliography. 
Matsuda, S. : On the Anatomy of Magnoliaceae. Journ. Coll. Sci. Imp. Univ. Japan, vi, 1894. 
Parmentier, P. : Histoire des Magnoliacees. Bull. Sci. de la France et de la Belgique, 
vol. xxvii, ser. R, 1895. 
Petit, L. : Le petiole des Dicotyledones au point de vue de l’anatomie comparee et de la 
taxinomie. These, Bordeaux, 1887. 
Plitt : Beitrage zur vergleichenden Anatomie des Blattstiels der Dicotyledonen. Diss., Marburg, 1886* 
Solereder : loc. cit. 
Vesque: Les tissus v^getaux appliques a la classification. Nouv. Arch. d. Mus. d’Hist. Nat., 
ser. 2, vol. iv, 1881. 
CALYCANTHACEAE 
Stem 1 : As regards the cylinder there is nothing special to narrate, the 
peculiarity of this stem is the presence of the four ‘ cauline ’ cortical bundles 
with inverted orientation of their parts (Fig. 25). Starting from a typical 
region of the axis and tracing the vascular system upwards we find on 
approaching a node that the four cortical bundles begin to divide up in the 
tangential direction, the two on one side of the stem (corresponding to the 
two opposed edges of two distinct leaves) being far ahead in this procedure 
of the two on the opposite side. A large bundle passes off from the 
cylinder to form the main strand of the leaf. This then gives off a bundle . 
which joins the dividing cortical bundle. From the latter a bundle is now 
given off at right angles to form one of the lateral bundles of the leaf. 
Both cortical bundles on the same side then divide up greatly to form 
a single continuous lengthy strand which constitutes a horizontal connexion 
between them. Then a second bundle, smaller than the first one, is 
given off to the lateral region of the leaf, and at the same time a phloem- 
strand is seen running up towards the midrib-bundle ; this is a strand 
joining the axillary bud-bundles. Both xylem and phloem of the middle 
region of the horizontal connexion then die out, with the result that the 
two cortical bundles of that side remain over for the next internode 
above. 
Immediately subsequent to this the same sequence of events occurs on 
the opposite side of the stem. 
1 The entire description here given is equally true for both genera, viz. Calycanthus and 
Chimonanthus, and for all species of either. 
