400 Vegetable Pathology. 



trunk or body is in both their main support; the limbs and arms 

 of each ; the head or crown ; the hair or leaves ; both porous, 

 and exuding a sensible perspiration. The feet or roots, which 

 keep their bodies upright ; the epidermis and cuticle, which 

 varies, from the delicate film that covers the eye of the animal 

 and the parts of a flower, to the hard skin of the foot and the 

 equally hard bark of the oak ; the cellular membrane, under the 

 cuticle of each, which gives to each its colour, and which 

 causes the white of the European, and the black of the Afri- 

 can ; the flesh or wood ; the heart (cor), or the pith (core) ; 

 the blood and the sap ; the veins through which the blood 

 flows, and those through which the sap is propelled ; the per- 

 spiration of both ; and, lastly, that peculiar construction, 

 which adapts each to live in the earth, or in the water, or 

 renders them both amphibious. All these analogies, and many 

 others, show the resemblance of each in their material parts, 

 uninfluenced by that medullary part which I denominated the 

 mind, and in which consists the chief distinction between 

 them. 



Food. — The analogy is still more strongly marked, when 

 we consider the necessity there is for each, not only of having 

 food for nourishment, but of having that food wholesome and 

 appropriate. Vegetables as well as animals are enfeebled by 

 improper nourishment; and as animals, having mincT, can 

 refuse whatever is improper, so vegetables, having no power 

 of choosing, must take whatever we give them. Here again 

 is an important distinction between the two, arising from the 

 passive nature of the one, and the voluntary action of the 

 other. Every practical agriculturist must daily witness the 

 effect on vegetables, grain, and plants, produced by soils more 

 or less adapted to their different natures, or powers of secre- 

 tion ; and how, as in animals, so in vegetables, their vigour, 

 growth, and even existence, depend on the quality and quan- 

 tity of their food. The knowledge of soils and manures, 

 which are the diet of plants, is essentially necessary to the 

 farmer and gardener ; as it is from this food that the fibres of 

 all roots collect what is necessary for the support of the parent 

 stem. The veins of vegetables are the sap-vessels, as the 

 veins of animals are the blood-vessels, to convey their nourish- 

 ment to every part of the tree ; and as the chyle poured into 

 the veins, and mixed with the blood, is, through the medium 

 of the heart ; so the nutrimental juices of plants, taken up 

 from the earth, are carried by sap-vessels into the leaves, for 

 similar purposes. Thus, the improved sap, like the arterial 

 blood, proceeds to nourish and invigorate the whole frame ; 

 and the secretions which each is able to form, from the sub- 



