* 



120 A DISCOURSE 



BOOK II. arising from so many, and such different causes. Whenever, therefore, 

 ''^''"^''"'''^^ our trees and plants fail and come short of the fruit and productions we 

 expect of them, (if the fault be not in our want of care,) it is certainly to 

 be attributed to those infibrmities to which all elementary things are ob- 

 noxious, either from the nature of the things themselves, and in them- 

 selves, or from some outward injury, not only through their being unskil- 

 fully cultivated by men, and exposed to hurtful beasts, but subject to be 



or shrink, and after a little space extend them again, as if they had both life and sen- 

 sation. As it cannot be denied, but that man, kept long from motion, grows pale and 

 weak^ so, on the other hand, it is a certain truth, that motion or exercise renders hira 

 florid, stout, and healthy : for exercise enlarges the limbs, as Avicenna rightly observes. 

 Hence the rustic excels the courtier in strength of body and largeness of limbs, being used 

 to much walking, and other exercise ; and it is well known that the right hand of 

 mechanics, and other people inured to labour, is, for the most part, bigger than the left. 

 These obvious truths need no laboured demonstration. With plants it is the same. Those 

 in stoves and green-houses, though they have sufficient heat and nourishment, are slender, 

 weak, and lose the colour of their leaves, and seem to languish for want of motion : and 

 trees, surrounded with high walls or buildings, and confined within narrow bounds, are 

 slender, and grow tall, but not strong. Pines in very thick woods, where the high winds 

 have not free access to shake them, grow tall and slender ; while others planted in open 

 fields, and frequently shaken by stormy winds, have not only thick and strong stems, but 

 also strike deep root, and put out beautiful and spreading branches. 



2. ANATOMY. Malpighi and Grew, unknown to each other, undertook the anatomy 

 of plants nearly about the same time. Many things, however, have been found out since 

 their days — and many things remain yet to be discovered. 



The general and obvious parts of a plant are five. The root; the stem ; the branches ; 

 the leaves ; the flower. The component parts of these divisions are simple in comparison 

 to the animal body. The offices of a vegetable being only increase and fructification, there 

 was no necessity for a complicated structure. — A good microscrope discovers tlie con- 

 stituent parts of a plant to be, 1. A very thin outer rind. 2. An inner rind much thicker 

 than the former. 3. A blea, of a spongy texture. 4. A vascular series. 5. A fleshy 

 substance, which answers to the wood of a tree, or shrub. 6. Pyramidal vessels contained 

 within the flesh. And 7. A pith.— Whatever part of the plant we examine, Ave observe 

 these, and no more. The root, its ascending stalk, and descending fibre, are one, and not 

 three substances. This reduces the entire vegetable to one body ; and what appears in 

 tlie flower to be many parts, are only the extremities of the seven above-mentioned. The 

 cup temiinates the outer bark. The inner rind ends in the outer petals. The blea forms 

 the inner petals. The vascular series ends in the nectaria. The flesh makes the filaments. 

 The pyramidal vessels fonri the receptacle. The pith furnishes the seeds and their 

 capsules. Words not being able to convey an adequate idea of these parts, I must beg 

 leave to refer the reader to the engravings of Dr. Hill, as published in his Vegetable 



