7^ PROFESSOR HENFREY ON THE DEVELOPMENT OF THE OVULE 



cular line is seen leading from the apex of the placenta to the point corresponding to the 

 base of the style ; the cells of the endocarp exhibit a radiating liaear arrangement on the 

 upper half, the lines running upwards and outwards from the placenta (fig. 27). 



A remarkable phenomenon occurs meanwhile in the interior of the placenta. It has 

 been stated that there is never any appearance of development of cells in that part of the 

 eml)rvo-sac, behind (or below) the septum formed a little way outside the nucleus 

 Tab. XVII. figs. 7-12). The inner bulbous expansion, formed by the septiun itself, which 

 becomes convex, and protruded upwards into the centre of the larger bulb, is found in the 

 same condition, as long as the sti'uctures are traceable, and it finally forms a kind of stalk 

 or "funiculus" to the seed, inserted into the substance of the albumen (Tab. XVII. 

 figs. 12, 17, and Tab. XVIII. fig. 26), and connecting this with the remains of the placental 

 structm-e. I have already mentioned, that while the tubular prolongation of the embryo- 

 sac, outside the nucleus, is growing up over the placenta, the posterior end, inside the 

 nucleus, also grows up, breaking down the tissue before it, into the substance of the placenta 

 (Tab. XVII. fig. 4). Within this organ it proceeds nearly to the summit, and then tm-ns 

 round somewhat suddenly, and grows down again, with various ramifications, in the 

 centre of the placenta, and even into the receptacle below where these arise (Tab. XVIII. 

 figs. 20, 21) : I have never seen anything like ceU-formation, or even production of septa 

 in these posterior branches of the embryo-sac ; they contain a granular protoplasmic 

 substance, which, in my preserved specimens, is of a red colour'. The ends of the barren 

 embryo-sacs imdergo the same kind of development mtliin the placenta, although the 

 changes in the external portion cease at the period of the formation of the germinal 

 vesicle. The ramifications of the three distinct embryo-sacs become somewhat inter- 

 laced, but I have never certainly detected any conjunction or adhesion of them, as 

 suspected by Griffith. 



It remains only to notice the further changes exhibited by the ovule. The endosperm 

 or albumen of the embryo-sac increases enormously in quantity, so as to expand the sac 

 in all directions (Tab. XVIII. figs. 16, 20, 26) ; the placenta is broken off just below the 

 point of origin of the ovules (fig. 26), and pushed outwards and upwards by the enlarge- 

 ment of the albumen (Tab. XVIII. figs. 27, 28 jj) ; in the ripe fruit it is found lying upon 

 the surface of the latter (Tab. XVIII. figs. 30 & 32^), which, through the displacement 

 and destruction of the endocarp, is finally in immediate contact with the woody mesocarp. 

 On examining the remnant of the placenta, even in the ripe fruit, it is found to be connected 

 with the endosperm by the bulb. When the placenta is then broken away from the 

 receptacle, and pushed up, the receptacle upon which it was seated is also carried away 

 towards the same side of the albumen, on the outside of which, near the base, it is 

 ultimately found (Tab. XVIII. figs. 28, 30, 32 c) as a littlo mass of sphacelated tissue 

 overlying a pit or foramen, which leads to an internal dark line, running through the 

 endosperm to the cotyledonary extremity of the embryo (Tab. XVIII. fig. 30 v). In this 

 line, and in the sphacelated mass, are foiind remains of the posterior ramified processes of 

 the embryo-sac, some of which are also found attached to the upper fragment or placenta*. 

 In the ripe seed, the embryo is found lying a little out of the axis of the albumen, in a 



* This seems to resemble what Mr. Bentham describes in O/acacea, Linn. Trans, xviii. p. 675. 



