PART II. 



LECTURE VI 



IMPORTANCE OF OBSERVING EXTERNAL, OBJECTS — VEGETABLES CONSIST OF TWO , 

 SETS OF ORGANS — OF THE ROOT. 



The exercises which constitute the principal part of our previous 

 course of lectures, are chiefly designed to assist you in practical bot- 

 any. It Is not expected that you are to be the passive receivers of 

 instruction, but that you arc to compare with real objects, the de- 

 scriptions which are presented ; by doing this faithfully, you will find 

 your minds gradually strengthened, and more competent to compare 

 and judge in abstract studies, where the subjects of investigation are 

 in the mind only, and cannot, like the plants, be looked at with the 

 eyes, and handled with the hands. 



All our thoughts, by means of the senses, are originally derived 

 from external objects. Suppose an infant to exist, who could neither 

 hear, see, taste, smell, nor feel ; all the embryos of thought and emo- 

 tion might exist within it; it might have a soul capable of as high at- 

 tainments as are withiii the reach of any created beings ; but this 

 sdUl, while thus imprisoned, could gather no ideas ; the beauty of 

 reflected light, constituting all the variety of colouring ; the harmony 

 of sounds, the fragrant odours of flowers, the various flavours, M^hich 

 are derived from our sense of taste, the ideas of soft, smooth, or 

 hard ; all must for ever remain unknown to the soul confined to a 

 body having no means of communication with the world around it 

 The soul, in its relation to external objects, may be compared to the 

 embryo plant, which, imprisoned within the seed, would for ever re- 

 main inert. Were no means provided for its escape from this confijie- 

 ment, and no communication opened between it and the air, the light^ 

 and vivifying influence of the earth. 



Since our first ideas are derived from external nature, is it not a 

 rational conclusion that we should add to this original stock of 

 knowledge, by a continued observation of objects addressed to our 

 senses ? After the years of infancy are past, and we begin to study 

 books^ should we, neglecting sensible objects, seek only to gain ideas 

 from the learned ; or, in other words, should we, in the pursuit of 

 human sciences, overlook the works of God? 



Having now enabled you to understand the method of analyzing 

 plants, we shall proceed to consider more fully the different organs 

 of plants, with the uses of each, in the vegetable economy. 



In plants, as well as animals, each part or organ is intimately con- 

 nected With the whole ; and the vegetable, as well as the animal be^ 

 ing, depends for its existence on certain laws of organization. 



We shall consider the vegetable organs under two classes; the 

 first, including such organs as promote the growth of the plant, as the 

 root, leaves, &c. ; the second, such as perfect the seed, and thus pro- 

 vide for the reproduction of the species, called organs of fructifica- 

 tion. 



Study of external objects stre'hgthens the mind — Abstract studies facilitated by ac- 

 quaintance with the natural sciences — Our first ideas gained by the senses— Analogy 

 between the soul and the erribryo plant— We should not confine our attention exclu- 

 sively to books—Vegetable, as well as animal existence, depends on certain laws of 

 organization — Two kinds of organs of vegetables. 



