558 
EXPLANATION OF THE PLATES. 
Fig. 36. Mode in which the pollen acts upon the stigma in (Enothera biennis ; 
a a, pollen-tubes ; b b, tissue of the stigma into which these tubes penetrate ; 
after Brongniart. 
Fig. 37. Mode in which the pollen acts upon the stigma in Antirrhinum majus ; 
after Brongniart : the pollen sticks to the surface of the stigma, and the tubes 
plunge down between the utricles of cellular tissue, of which the stigma 
consists. 
Fig. 38. A grain of pollen of the same plant with its tube, more highly mag- 
nified : a, the pollen-tube. 
PLATE V. 
Fig. 1. Vertical section of the ovarium of Dictamnus albus j a, gynophorus, or 
elongated base of the ovarium ; b, base of the style ; c, cavity where the car- 
pella have not united ; rf, cell ; e, placenta, with ovula attached to it. 
Fig. 2. Transverse section of the same in a more advanced state, where the car- 
pella are beginning to separate : a a, carpella ; b, an ovulum cut through ; 
c, placenta. 
Fig' 3. Pistillum of Coriaria myrtifolia ; consisting of five carpella, each bearing 
a single linear stigma, and collected round a common elevated axis, the base of 
which is seen at a. 
Fig. 4' Ovarium of Lamium album; a, base of the style; b, carpella pressed 
together into a square concave body ; c, fleshy lobed disk. 
Fig. 5. Pistillum of Pinguicula vulgaris; a, ovarium ; b, style; c, stigma con- 
sisting of two very unequal lobes. 
Fig' 6. A vertical section of the same ; a, the central free placenta ; 6, ovula ; 
c, point where the placenta is connected, before fertilisation, with the stig- 
matic tissue. 
Fig. 7. A perpendicular section of the pistillum of Vaccinium amoenum j a, 
inferior ovarium combined with the tube of the calyx ; by limb of the calyx ; 
c, epigynous disk; d, placenta; e, ovula;/, style; g, stigma. 
i^iff. 8. A transverse section of the ovarium of Hydrophyllum canadense, showing 
its remarkable placentation ; a, wall of the ovarium ; b, left placenta ; c, right 
placenta; e, one of their points of union, the other is seen on the opposite 
side ; d, a fleshy secreting annular disk. In this case, two placentae grow up 
face to face from the base of the ovarium, and gradually unite at their edges, e, 
enclosing the ovula within the cavity they thus form ; this is proved by Ne- 
mophila, in which the placentation is the same, except that the placentae are 
always distinct from each other; one of these placentae, the ovuliferous face 
turned towards the eye, is represented at fig. 8. 
Fie 9. A perpendicular section of the inferior ovarium of Thamnea uniflora, 
after A. Brongniart; a, tube of the calyx ; 6, wall of the ovarium ; c, epigynous 
disk ; d, ovula collected round a columnar placenta. 
Fig. 10. Transverse section of the ovarium of Viola tricolor, showing its parietal 
placentation ; a, one of the three placentas. 
Fig. 11. Stigma of the same plant, which is inflated and hollow, with an orifice 
obliquely situated at its apex. 
Fig. 12. Bifid stigma of Chloanthes stoechadis, after Ferdinand Bauer. 
Fig. 13- Hairy apex of the style and stigma, with its indusium, of Brunonia 
australis, after Ferdinand Bauer ; a, stigma ; b, indusium. 
