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The anatomy of plants

Chapter 102: CHAP. VII.
By Nehemiah Grew
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About This Book

This work presents a systematic, observational study of plant structure and function, describing the internal organization of seeds, roots, stems, leaves, flowers, fruits, and seeds as revealed by close inspection and a microscope. It maps tissues and organs, explains the movement of sap and air, and analyses the generation and distribution of plant fluids and substances such as milks, oils, and salts. Additional lectures examine leaf and flower anatomy, coloration, tastes, and soluble salts, and the text includes comparative tables and explanatory notes to support a mechanical and physiological account of vegetation.

CHAP. VII.

Of the USE of the Parts to the Seed. And the TIME, in which the Uterus or Fruit and Seed-Case are formed.

ND first, for example, in an Apple, the Five Inmost Branches, do best serve for the Generation of the Seed; these running into the Attire of the Flower, and so carrying off the most Aerial Spirit from the Seed; P. 2. Ch. 5. §. 5. by which means, it becomes a more compact and denser Body, than the Fruit, and so more accommodate to the process of Vegetation; as hath formerly been shewed.

2. §. The Elongation likewise of the Seed-Vessels, in the Fruit and Case, sometimes directly, as in Plums and Nuts, and sometimes by several Ambages before they shoot into the Seeds, as in Tulip; shewes a design for the highest refining and maturation of the Seminal Sap.

3. §. Chiefly by means of the Inmost Vessels, is made that Chanel in some Pears, and especially in Quinces. For these perishing with the Flower, the circumjacent Parenchyma shrinks up, leaving the said Chanel in the midst. Designed for an inlet to the Aer, for the better drying of the Seeds; which here stand the more in need of it, because encompassed with a Mucilage.

4. §. For the better drying of the Seed, and the disbursing or sowing of it in due time, the opening of the Case is, in the same manner, also contrived: either at the Top, as in Popy; or on the Sides, as in Tulip, Pimpernel; or at the Bottom, as in Coded Arsmart. All which openings are effected by the running of the Aer-Vessels along those places: for by drying the Parenchyma next adjacent, they cause it to chop and cleave asunder.

5. §. Of the Seed-Case of Poppy, it is particularly to be noted, That as the several Windows, serve to let in Aer, for the drying of the Seeds, after their full Growth: So the Canopy over them, serves to keep out Rain. For here, the Case not cleaving down the Side, as it usually doth; should the Rain get in, it would stand in it, as in a Pot, and so rot the Seeds. And as the Canopy serves to preserve the Seeds; so the several Partitions or Walls, for their better Stowage. For by an easie survey of this little piece of Ground, it is plain, that as they stand on both Sides every Wall, there is as much more Ground for them to stand upon, as if there were no parting Walls, but the Seeds stuck all round about upon the Ambit or Sides of the Case; or upon a great Bed or Placenta within it, as in Hyoscyamus, Anagallis, &c. where there is a less numerous Brood.

6. §. The Coar likewise, by standing betwixt the moyst Parenchyma and the Seed, and being hollow and so filled with Aer; doth much conduce to the ripening and drying of the Seed, and its greater fitness both for keeping, and sowing. So the Parchment Lining of the Seed-Case, as in Hyoscyamus, &c. is answerable to a Coar.

7. §. The Parenchyma serveth, amongst other purposes, for the Generation of the Covers of the Seed; as in some instances hath been shewed. For which intent, sometimes the Exterior Parenchyma, as in a Limon; sometimes the midlemost, as in a Goosberry or Cucumer, is subservient; both of them, in those Fruits, being more white and dry, than the rest, and so fiter to make the Covers of the Seed.

8. §. The Parenchyma is also of use for the warmth of the Seed; as in the Seed-Case of Garden Radish. Wherein, as it ripens the Parenchyma gradually drys, breaks, and shrinks up into several soft Membranes, in which the Seeds, in the Centre of the Case, lie swadled, as in so many fine Calico Cloths.

9. §. I SHALL conclude with observing the Time of the Generation of the Fruit and Seed-Case. This hath hitherto been thought to be initiated upon the opening, I say not, the forming, but the opening of the Flower, or not long before. Notwithstanding which, what I have formerly said of the Flower; I now do the like, of the Uterus it self; sc. That in very many Plants, ’tis formed, with the Flower, the year before it appears and comes to its full Growth. Tab. 71. As for instance, in Azarum, not only all the Parts of the Flower, but the Uterus it self, and there in also the outer Cover of the Seed of any one year, are perfectly formed in August or September of the year foregoing. The like may be seen in Tulip, Mezereon, Corin, and many other Perennial Plants.