324 MORPHOLOGY. 



flat, and those between the germens hemispherical or conical, convex 

 (the remaining Itosacece, fig. 185.). Yet more striking is the difference 

 in Passiflora, where a flat disc bears upon its edge the calyx and corolla, 

 whilst the internode between this and the stamens is elongated in its 

 upper part, and that between the stamens and the germens in its whole 

 extent (Plate IV.). 



Sometimes individual internodes of the flower appear strikingly 

 developed ; this most frequently occurs in the gynophore, in the Labia- 

 tce and Boraginacece, as a thick fleshy disc (gynobasis) ; in the Malvacece 

 as a thick, conical body, bearing the circle of germens; in Ranuriculacea 

 (e. g., Myosurus) and in Magnoliacece as a long, almost cylindrical,, organ.* 



No word has been so falsely used as the word discus ; all the peculiar 

 organs found in the flower, which could not be reduced to the four 

 common forms calyx, corolla, stamen, or pistil have been heaped 

 together under the term discus. Thus in the Thymeleacece decided, even 

 perfectly free, foliar organs ; in the Scrophularinecp, and allied families, 

 a circle of coherent foliar organs (termed also annulus hypogynus) ; 

 in the UmbellifercB, the somewhat fleshly and succulently developed 

 lower part of the carpels (as discus epigynus) ; and the like. An infinity 

 of special conditions still remain to be 'investigated and explained; I 

 can only offer the few which I have had time to examine ; a complete 

 working out of these conditions would be a most meritorious task, and 

 would be of infinite assistance in the recognition of natural affinities ; 

 but one must not restrict oneself to calling a discus every yellow and 

 rather succulent body one finds in the flower. 



I cannot repress here a teleological observation, which I own is not 

 scientific. We do find the discoid and cup-like form in other axial 

 organs, but nowhere so frequently as in the internodes of the flower : 

 this is, however, unquestionably the simplest means to produce a con- 

 dition of things favourable to a great multiplicity of structures, without 

 injury to the dimensional connection and apparent individuality and 

 completeness of the flower. 



B. NUMBER, RELATIVE POSITION, AND DURATION OF THE PARTS OF 



THE FLOWER. 



147. It is very rarely that a flower consists of one part only, 

 as in the male flowers of Euphorbia^, Lemna, and Wolffia, which 

 are formed of one foliar organ, the anther ; or the female flower 

 of Taxus, which is formed of one axial organ, the seed-bud. 

 Usually more parts unite to form a flower : thus the female flower 

 of most of the Aroidece consists of one or more seed-buds, and a 

 carpel surrounding them. The male flower of the Salicinecs con- 

 sists of a scale-like disk and several stamens. In the generality of 

 cases, male and female organs are both present in the same flower : 

 they are seldom naked, as in Hippuris, but usually surrounded by 

 floral envelopes. 



* Analogous to the disc in the Boragineae and Labiate, the axis in the Crucifera 

 and Alsineas forms tumefactions on the base of the stamens, which surround the bottom 

 of the pistil as little scales or a little cup, and are usually described as inferior glands, 

 because they often secrete sweet viscid fluid through the epithelium, which remains 

 very delicate. 



f Here the single stamen (foliar organ) stands exactly on the middle and the end 

 of the little pedicel. A complete history of the development is still a desideratum. 



