THE SEED. 39 



ripened them. The outer skin of the seed, called the " testa," is 

 often of some beautiful colour, as in French and scarlet beans, 

 where it is variously mottled with white, purple, brown, violet, and 

 other colours. The seeds of other plants of the Pea-family, brought 

 from tropical countries, are remarkable for their brilliant orange- 

 colour and scarlet, and the polished and shining surface. Seeds of 

 many English wild-flowers are equally beautiful, though requiring the 

 microscope for their peculiar character to be seen. Those of the 

 Carnation-family, the poppy, and the henbane, appear as if carved and 

 embossed with tubercles ; and those of orchideous plants resemble 

 purses made of fine net, each with a piece of money in the centre. 

 On opening the seed, it is found to consist of white matter. This is 

 generally resolvable into two distinct portions, as well shewn in an 

 almond or a walnut, each being a " seed-leaf" or " cotyledon." They 

 are connected at one end by a kind of hinge, which is the " embryo " 

 or basis of the future plant. At the period of germination the embryo 

 strikes a little rootlet into the ground, the testa being ruptured by the 

 swelling of the whole mass, and often lifts the cotyledons into the air, 

 where they become green, and are the sign that the seeds are " coming 

 up." Sometimes they remain in the ground, and the embryo pushes 

 up a "plumule," which is the beginning of the future stem, and soon 

 commences to unfold little leaves. There are many seeds, however, 

 where the cotyledons are extremely minute, and lodged in a quantity 

 of floury matter, which nourishes the embryo when it germinates. 

 The purpose of the cotyledons is likewise to supply nourishment while 

 the plant is yet too weak and tender to procure food from external 

 sources. Hence they have been compared to the breasts of nursing 

 mothers, and it is not difiicult to see how many and close are the 

 points of resemblance. While fruits are often so small as to be mis- 

 taken for seeds, the latter, in their turn, are often so large as to 

 resemble nuts and other fruits. This is the case with the seeds of the 

 horse-chesnut, and with many that are brought as curiosities from 

 tropical countries. There is an infallible distinction between a fruit 

 and a seed, however much they may resemble ; — the fruit always has 

 a scar at the base, shewing where it was attached to the peduncle, 

 and another upon the summit, indicating the former presence of the 

 style or stigma ; but the seed has never more than one scar, indicating 

 the point at which it was connected with the placenta of the pod that 

 contained it, and corresponding to that part of the body which anato- 

 mists and artists call the umbilicus. 



