616 DR. M. T. MASTERS ON THE PASSIFLORACE X. 
nucleated cells, from the inner surface of which a quantity of very large thin-walled 
nucleated cells are formed, constituting the pulp which invests the seed. The primine 
is also a mere sheet of cellular tissue, consisting of oblong, flattened, nucleated cells. 
The secundine is the layer which chiefly contributes to the thickness of the hard “ testa ” 
of the seed. In the young state it is thick and fleshy, presenting on the outside (in.P. 
alba) numerous pits, which form conical elevations on the inner surface. These funnel- 
like processes appear at first to be pervious at the apex (see Plate LXIV. fig. 28), so that 
direct communication exists between the outer and inner portions of the ovule; but 
ultimately the perforation becomes closed at the inner end. : 
The constituent cells of the secundine ultimately become thickened by the formation 
of secondary deposits within them, so that, as before said, the mass of the hard testa of 
the seed, which retains its pitted appearance, is derived from the secundine. 
FERTILIZATION OF THE FLOWER. 
My remarks on this subject apply solely to the genus Passiflora, and refer chiefly to 
the functions exercised by the corona. Late in its development, and complicated in its 
arrangement, the series of parts constituting the corona seem to have some special office 
to fulfil in connexion with the fertilization of the flower. In the first place I may 
refer to the comparative rarity with which some of the species ripen their fruit unless 
assisted by art; and not only this, but it has also been. observed that in some cases fruit 
is not formed idee the flower be impregnated with pollen of some other species! A 
summary of the evidence on this point is given by Mr. Darwin*, to whose remarks 1 
would merely add that ripe fruit is often formed when perfect seeds are not. This is 
particularly observable in certain hybrid forms, such as x P. hybrida floribunda or 
X P. ceruleo-racemosa. 
* That the tendency in Passion-flowers is against self-fertilization and in favour of cross 
impregnation might, I think, be inferred from the arrangement of the parts of the 
flower, even if the fact were not known practically. 
* * Variation of Animals and Plants, ii. 137; Scott, * Journ. Linn. Soc.’ viii. (1864) p.197. It is, however, certain 
that many species will ripen perfect fruit and seeds after fertilization by their own pollen. Some species (e. g. P. alba) 
do this without artificial assistance ; and the common P. cerulea may be observed, in favourable seasons and localities, - 
bearing ripe fruit and seeds out of doors. Mr. Ridout, a practical gardener of much experience, furnishes me with 
the following note on this matter :—“ The extract from Mr. Darwin's * Variation of Animals and Plants under Do- 
mestication” is not in accordance with my own experience. . In one instance I have succeeded in fruiting P. racemosa, 
fertilized by its own pollen; the fruit swelled freely and evenly to the full size attained by that species; while, in 
the case of P. quadrangularis, for several years past I have been in the habit of setting, not a few fruit, but several 
dozens, entirely by its own pollen, and have at this time a plant of that species covering the roof of a small 
lean-to house, with upwards of 100 fruit on it, this being the third crop it has produced this year, the two former 
equalling the present in point of number. I impregnate them when there is a good number of flowers expanded at 
one time, after which the temperature of the house is allowed to rise from 5? to 10? for the remainder of 
the nr: ; and it has always proved a rare case for one to fail; in fact, they set with much greater certainty than 
ns. I know also that Mr. Mundell, of Hooley Hall, has been even more successful than myself; for he has 
annually excellent eroe of the Granadille, and fruit of P. edulis. Nor has his attention been confined to these alone; 
for three 'eautift ve nde Jen reet ak Qui ubi have already emanated from there." 
