SEED OR MA.TUEB OVULE. 329 



it has been called by some an arillode. This arillode, after growing 

 downwards, may be reflected upwards, so as to cover the foramen. 



On the testa, at various points, there are pro- „ 



duced at times cellular bodies, which are not 

 dependent on fertilisation, to which the name of 

 strophioles (strophiolum, a little garland), or car- 

 mioales {caruncula, a little piece of flesh), has been 

 given, the seeds being strophiolate or carunculate. 

 These tumours may occur near the base or apex of 

 the seed, they may be swellings of the exostome, 

 as in Eicinus (fig. 579 c), or they may occur in the 

 course of the raphe. ^'s- ^'^^■ 



Seeds are attached to the placenta by means of a funiculus or 

 umbilical cord, which varies much in length. In Magnolias it attains 

 a great length, and when the seed is ripe it appears like a cord sus- 

 pendrog it from the follicle. The point of the seed by which it is 

 united to the cord, or the soar left on its separation, is called the hilwm 

 or umbilicus, and represents its base. The hilum frequently exhibits 

 marked colours, being black in the Bean, white in many species of 

 Phaseolus, etc. It may occupy a small or large surface, according to 

 the nature of the attachment. In the Calabar bean and in some 

 species of Mucuna and Dolichos it extends along a large portion of the 

 edge of the seed. The part called the foramen in the ovule becomes 

 the micropyle (/iix^og, small, and ■ruX>i, gate) of the seed, with its 

 exostome and endostome. This may be recognisable by the naked eye, 

 as in the Pea and Bean tribe. Iris, etc., or it may be very minute and 

 microscopic. It indicates the true apex of the seed, and is important 

 as marking the part to which the root of the embryo is directed. At 

 the micropyle in the Bean is observed a small process of integument, 

 which, when the young plant sprouts, is pushed up like a lid, and is 

 called emiryotega (tego, I cover). The flbro-vascular bundles, from the 

 placenta pass through the funiculus and reach the seed, either entering 

 it directly at a point called the omphalode (ofi,(paX6g, navel), which forms 

 part of the hilum, or being prolonged between the outer an,d inner 

 integument in the form of a raphe Qdip^, a seam), and reaching the 

 chalam (■^dXal^a, a pimple or tubercle), or organic base of the nucleus, 

 where a swelling or peculiar expansion may often be detected, as in 

 Crocus. In fig. 576 the spiral vessels, r, are seen entering the cord, /, 

 passing through the hilum, h, forming the raphe, r, between the testa, i, 

 and endopleura, mi, and ending in the chalazal expansion, c. So also 



Kg. 679. Vertical section of a carpel of Bioinus communis, and of the seed which it 

 contains, a. Pericarp. I, Looulament. /, Funiculus or umbilical cord, t. Integuments of 

 the seed, having at their apex a caruncula, c, which is traversed hy the small canal of the 

 exostome. The exostome does not correspond exactly with the endostome, which is imme- 

 diately above the radicle, r, Eaphe. cS., Chalaza, p. Perisperm or albumen, the upper 

 portion of which only is seen, e, Embryo, vnth its radicle, er, and its cotyledons, ec. 



