84 THE COMMENCEMENT OF THE PHANEROGAMIC FRUIT. 



the ovule. It is sometimes attached to the wider end of the tube (212 ^^), hut more 

 frequently it arises from the narrowed base as a tiny, conical projection inclosed in 

 a circular envelope of its own (212^^). This envelope corresponds to the inner, and 

 the tube to the outer integument of the ovule. 



From a study of these monstrous flowers it would appear that when the ovule 

 possesses two integuments, the outer one corresponds sometimes to the whole apical 

 portion of a carpel, sometimes to but a segment of a carpel; the former being the 

 case when carpels of two kinds are present, and when, at the centre of the floral 

 receptacle, above the outer non-ovule-bearing carpels, only a single fertile carpel is 

 produced. The inner integument, on the other hand, arises like a corona from the 

 leaf -like outer one. 



The nucellus of the ovule arises in many instances {e.g. in Orchids) from a mass 

 of tissue produced by the division of a single epidermal cell, but in by far the 

 majority of cases at the margin or upon the surface of a leaf or leaf-segment, 

 resembling in all respects a foliar bud. 



That the ovule can be produced directly from the floral receptacle is not yet 

 ascertained with certainty, though such an origin would appear to be not improbable 

 in the Pepper family. That is no good reason why ovules should behave differently 

 from bud-like brood-bodies, which arise sometimes from leaf- and sometimes from 

 stem-structures. So great is the analogy between ovules and detachable buds, that 

 ovules formerly received from Botanists the name of "seed-buds". In this con- 

 nection it is very instructive to contrast the ovules in the ovary of certain Orchids 

 with the foliar buds produced on the leaves of some of these plants. In Malaxis 

 paludosa {cf. fig. 200^, p. 41) the foliar buds are found partly on the upper surface 

 of the leaf, partly on the margins, forming in the latter case a fringe. They con- 

 sist of a compact, central portion inclosed in a large-celled envelope which is so 

 fashioned that the whole structure resembles an ovule {cf. fig. 200*^). So striking 

 is this resemblance, that anyone unacquainted with the fact that these buds arise 

 from foliage-leaves would unhesitatingly regard them as ovules. Later on, of 

 course, differences appear, in that in the ovule an independent embryo is produced, 

 whilst the bud gives rise to a shoot, which must be regarded as a branch of the 

 parent plant. This is, of course, an important distinction, and applicable to the 

 majority of cases, though not quite to all. The parthenogenetically produced brood- 

 bodies, to be treated fully by and by, have both the form of true embryos and 

 occupy the same position in the ovule beneath the micropyle. Were it not known 

 that the hard, indehiscent fruit (achene) of Gnaphalium alpinum { = Antennaria 

 alpina), with the rudiment of another generation which it contains, is produced 

 without the intervention of pollen, without fertihzation, it would certainly not be 

 apparent from its structure. From this we may conclude that the distinction 

 between bud and ovule, between brood-body and fruit, cannot be based on purely 

 structural characters, and that fruits and brood-bodies are sometimes interchange- 

 able — facts of great importance in solving the question of the importance of 

 fertilization in the origin of new species. 



