190 REV. PROF. G. HENSLOW ON THE 
many * points" as there are pedicels in the umbel (2). Each 
becomes rounded and throws off an are of cords for the braet (3). 
The remainder form a series of ares (4). They finally separate 
as pedicels, each of which contains five cords by coalescence of 
the superfluous ones (5). The five cords of the pedicels rapidly 
increase by radial chorisis to ten and become confluent at the 
base of the calyx (6). They then send off five cords for the calyx 
and five for the corolla (7, 8). The latter subsequently supply 
the epipetalous and superposed stamens. Five other rudi- 
mentary cords superposed to the sepals represent the lost or 
arrested stamens (7, 8, ar.st.). The remaining cords form a ring 
with ten lobes. These become resolved into ten placental (9, pl.e.) 
cords and five dorsal (9, d.). Besides the five dorsal, five other 
small cords are thrown off to pass up the wall of the one-celled 
ovary (10); while the ten larger ones enter the base of the 
free-central placenta. The tracheæ are central within the phloém, 
and not oriented as if axial*. They form a tolerably correct 
circle in the specimens examined; but in a Himalayan species 
the grouping was distinctly pentangular with five cords in front 
of the sepals. This clearly shows that the pistil is really com- 
posed of five carpels superposed to the sepals, and that the free- 
central placenta consists of ten margins fused together. 
Figure 11 represents a case I have met with in which the 
carpels of P. sinensis were dissociated and more or less foliaceous 
with rudimentary ovules, not only along the margins but with 
several borne on a “heel-like” process, which extends towards 
the centre of the ovary. This countenances the view that the 
free-central placenta of the Primulace is really carpellary, and 
not axial. Anatomy, as shown above, clearly bears this out t. 
With regard to the stamens being superposed to the petals, 
this is, of course, due to the arrest of the sepaline whorl. Rham- 
mus resembles Primula in having all the staminal cords in union 
with the petaline, but they part company at an earlier period 
than is the case in Primula. The cords are in fact distinct in 
the axis; whereas in Primula they do not become separate until 
a certain height is reached in the tube of the corolla. Rhamnus, 
however, differs from Primula in that no trace of the cords 
belonging to the sepaline stamens is discoverable, 
* Ph. van Tieghem, ‘Recherches sur la Structure du Pistil,’ p. 11, pl. ix. fig. 2, 
represents them as having the trachex on the inner side, i. e. as if axial. I did 
not find this to be the case. 
F See ‘Origin of Floral Structures,’ p. 76. 
