BOTANY. 



BOTANY. 



to elevation, exposure, climate, &c." And in ; 

 the first volume of their transactions will be j 

 found several valuable essays on the subject, j 

 by Mr. Macgillivray, p. 81, Mr. Gorie, p. 113, j 

 Dr. Singer, p. 264, Mr. Hogg, p. 271, all ably I 

 illustrating the value of the study of plants to j 

 the cultivator. 



The definition of a plant to a superficial ob- 

 server may appear easy; but those who have 

 studied natural history are aware of the diffi- 

 culty of drawing a just line of distinction be- 

 tween the animal and the vegetable kingdoms. 

 It is easy to distinguish a horse, or even a 

 worm, from a rose-tree or a fungus; but to 

 distinguish a sensitive plant, &c., by descrip- 

 tive marks from many zoophytes, has hitherto 

 baffled the acutest botanists. Many plants, as 

 will be presently seen, are gifted with sponta- 

 neous motion ; whilst many animals, as the 

 corallines, are devoid of locomotion ; so that 

 neither of these qualities avails us in distin- 

 guishing the two kingdoms. In short, whilst 

 the zoophytes, most of which take root, grow 

 up into stems, and multiply by buds and slips, 

 must still be considered as animals, no one 

 can correctly define how plants differ from 

 them. It is, however, fortunate, that the stu- 

 dent is seldom placed in a situation where 

 these nice distinctions are to be made. Where 

 specimens are to be examined which admit of 

 the doubt whether they belong to the lower 

 classes of animals or to the vegetable tribes, 

 chemistry may be called to our aid ; if, when 

 burnt, they omit an ammoniacal smell resem- 

 bling that of feathers, similarly treated, we 

 need not hesitate to consider them as animal 

 products ; if that of burning wood, we may 

 consider them as fit objects for our botanical 

 researches. 



A few facts will demonstrate that it is im- 

 possible to deny that vegetables possess some 

 degree of sensation. The Venus's fly-trap 

 (Dionaea muscipula) has jointed appendages to 

 the leaves, which are furnished on their edges 

 with a row of strong prickles. Flies, attracted 

 by honey, which is secreted in glands on their 

 surface, venture to alight upon them; no 

 sooner do their legs touch these parts than the 

 sides of the leaves spring up, and locking their 

 rows of prickles together, squeeze the insects 

 to death. The well-known sensitive plant 

 (Mimosa sensifiva and pudicd) shrink from the 

 slightest touch. Oxalis sensitive* and Smithfa 

 aensitiva are similarly irritable ; as also are the 

 stamens of the flower of the barberry. One of 

 this tribe (Hedysarum gyrans) has a sponta- 

 neous motion its leaves are frequently mov- 

 ing in various directions without order or 

 co-operation. When an insect inserts its pro- 

 boscis between the converging anthers of a 

 kind of dog's bane (Apocynum androssemifo- 

 /tum), they close with a power usually suffi- 

 cient to detain the intruder until his death. If 

 from these, and many other considerations 

 which we shall notice as we pursue our study, 

 we conclude that plants are endowed with a 

 certain degree of sensation, or at least of irri- 



t lability, we can pursue that path of the science 

 no further. Such are the results of life ; what 

 constitutes the living principle no human eye 

 can discover. 

 208 



We gaze on a rose as it waves in the pleni- 

 tude of its vigour, admire the tints of its petals, 

 the verdure of its foliage, the gracefulness of 

 its form, the delicacy of its fragrance. We 

 may come on the morrow, and it has been 

 blasted those petals are scattered on the bor- 

 ders those leaves are withered and sapless 

 and scarcely a vestive of its loveliness remains. 

 Wherefore is this change! The same "compo- 

 nents remain the same food was ready for its 

 nourishment; but some invisible governing 

 principle some unknown agent has silently 

 departed, without one vacancy to point out 

 where it had resided, but a total ruin, to show 

 that it had pervaded the whole. Let a few 

 more hours pass away, when the air, and 

 moisture, and heat, external agents which 

 were subservient to its welfare, now concur in 

 completing its destruction it is partly dissi- 

 pated in pestilential exhalations, partly reduced 

 to a few earthy and saline particles. Life, 

 whilst it continued, prevented this ruin ; but 

 still, like its Great Author, " no one hath seen 

 it at any time." 



To explore our path satisfactorily, and that 

 one step may naturally explain the way to 

 the succeeding, we had better first consider 

 the most obvious parts of plants, and their 

 functions. 



The root and its uses. A root usually consists 

 of two parts, the caudex or body, and the fibres 

 or radicula. The last only are essential for : 

 the imbibing of nourishment, but the whole I 

 serves to steady or fix the plant firmly in a I 

 commodious situation and position. Roots are I 

 annual, biennial, or perennial. The first be- | 

 long to those plants whose term of existence 

 is confined to a portion of a year, as barley ; 

 the second to such as, being raised during one 

 year, survive its winter, and produce flowers 

 during a succeeding year, as wheat. Perennial 

 roots belong to such plants as live for several 

 years. All plants are considered as biennials 

 that are raised from seed one year, and flower 

 during another, whether that year is the next, 

 or whether the flowering is deferred during ' 

 several, provided the flowers occur but once. 

 This is often the case with the tree mallow 

 ( Lavatera arborea), &c. Attention must be paid 

 to these circumstances, or we may often mis- 

 take the natural term of a plant's existence. 

 Mignionette (Reseda odorata), in our borders, 

 is an annual ; but in the shelter of a room or 

 green-house, it may be made, by proper ma- 

 nagement, to blossom during several succes- 

 sive seasons. The nasturtium (Tropseolum), 

 naturally a shrubby perennial, is an annual in 

 our gardens. 



Plants search for food by means of their 

 roots, and to obtain it have been known, by 

 their aid, to overturn walls by piercing their 

 foundations. A tree growing on the top of a 

 wall has been observed to extend its roots 

 down the sides, until they reached the earth at 

 its bottom. If a flower-pot, divided by a per- 

 pendicular section, be on one side filled with 

 common earth, and on the other with similar 

 earth mixed with a little potass, the roots of a 

 geranium or other plant, growing in it, will, 

 by degrees, all move into the alkaline portion. 

 It has also been proved that the root is gifted 





