^n 



PHANEROGAMS. 



nucellus; an annular wall grows up first, and finally envelopes the nucellus and 

 extends beyond it as an integument. If a second outer integument is formed in 

 addition, this arises in a similar manner, and grows up around the first (as in 

 Piperacese, Polygonaceae, &c.). The anatropous ovule may be at first a straight or 

 slightly curved projection of tissue (as in Fig. 397, /), but it immediately becomes 

 evidently curved at the spot where the first or the single integument springs from it 

 (Fig. 397, //, ///, IV^', the apical part enclosed by the integument then forms the 

 nucellus, while the subjacent basal part becomes the funiculus. As the integuments 

 arise, the curvature becomes gradually stronger, and the nucellus becomes inverted 

 even before the outer integument has entirely developed. This latter is therefore 

 not formed on the side next to the raphe, but clothes all the free part of the 

 ovule, right and left of the raphe (Fig. 397, F, VI, VII). Cramer was the first to 

 point out that anatropous ovules may originate in another way (and this is probably 



Fig. 398. — Ftinkia cordata; A horizontal section of the young superior trilocular ovary, two ovules 5A' are seen in each 

 loculus, growing from the revolute margins of the carpels, ^ a fibro-vascular bundle surrounded by light-coloured parenchyma ; 

 B and C two successive states of the young ovule in longitudinal section, KK tissue of the nucellus, zV inner, ia outer integument, 

 e embryo-sac {A slightly, B, C very highly magnified). 



the most common case), the ovule developing as a secondary lateral projection 

 beneath the apex of the young conical funiculus, and curving backwards subse- 

 quently towards the base of the latter. This inversion takes place while the single 

 or the inner integument is enveloping the nucellus from the summit of the funi- 

 culus ; the second integument, if there be one, then similarly clothes the free part 

 (see Fig. 398, B, C). Kohne ^ has indeed thrown some doubt on the actual lateral 

 origin of the nucellus, not only in Compositse, but also in Solanum, Hedera^ Fuchsia, 

 Begonia, &c. I have, however, had the opportunity of observing a number of 

 different stages of development in this respect, and not only of convincing myself 

 that the funiculus arises laterally with respect to the apex of the floral axis, but also 

 that the nucellus, when first visible, stands laterally also below the apex of the funi- 

 culus. It is possible that the observation of peculiarly favourable cases will remove 



^ Kohne, Ueber die BlUthenentwickelung bei den Compositen. Berlin 1866, [Kohne's view is 

 supported by Ilaenlein's observations (Beit. z. Entwickelungsgeschichte der Compositenbluthe, 

 Scheiik's Mittheilungen, II. 1875).] 



