[50] Exerc. lxiii.
[51] Bourdon, p. 221.
[52] Ib. p. 49.
Sect. 2.—The Examination of the Process of Reproduction in Vegetables.
The extension of the analogies of animal generation to the vegetable world was far from obvious. This extension was however made;—with reference to the embryo plant, principally by the microscopic observers, Nehemiah Grew, Marcello Malpighi, and Antony Leeuwenhoek;—with respect to the existence of the sexes, by Linnæus and his predecessors.
The microscopic labors of Grew and Malpighi were patronized by the Royal Society of London in its earliest youth. Grew’s book, The Anatomy of Plants, was ordered to be printed in 1670. It contains plates representing extremely well the process of germination in various seeds, and the author’s observations exhibit a very clear conception of the relation and analogies of different portions of the seed. On the day on which the copy of this work was laid before the Society, a communication from Malpighi of Bologna, Anatomes Plantarum Idea, stated his researches, and promised figures which should illustrate them. Both authors afterwards went on with a long train of valuable observations, which they published at various times, and which contain much that has since become a permanent portion of the science.
Both Grew and Malpighi were, as we have remarked, led to apply to vegetable generation many terms which imply an analogy with the generation of animals. Thus, Grew terms the innermost coat of the seed, the secundine; speaks of the navel-fibres, &c. Many more such terms have been added by other writers. And, as has been observed by a modern physiologist,[53] the resemblance is striking. Both in the vegetable seed and in the fertilized animal egg, we have an embryo, chalazæ, a placenta, an umbilical cord, a cicatricula, an amnios, membranes, nourishing vessels. The cotyledons of the seed are the equivalent of the vitellus of birds, or of the umbilical vesicle of suckling-beasts: [458] the albumen or perisperm of the grain is analogous to the white of the egg of birds, or the allantoid of viviparous animals.
[53] Ib. p. 384.
Sexes of Plants.—The attribution of sexes to plants, is a notion which was very early adopted; but only gradually unfolded into distinctness and generality.[54] The ancients were acquainted with the fecundation of vegetables. Empedocles, Aristotle, Theophrastus, Pliny, and some of the poets, make mention of it; but their notions were very incomplete, and the conception was again lost in the general shipwreck of human knowledge. A Latin poem, composed in the fifteenth century by Jovianus Pontanus, the preceptor of Alphonso, King of Naples, is the first modern work in which mention is made of the sex of plants. Pontanus sings the loves of two date-palms, which grew at the distance of fifteen leagues from each other: the male at Brundusium, the female at Otranto. The distance did not prevent the female from becoming fruitful, as soon as the palms had raised their heads above the surrounding trees, so that nothing intervened directly between them, or, to speak with the poet, so that they were able to see each other.
[54] Mirbel, El. ii. 538.