BOTANY. 



EOT AN V. 



to elevatijn, exposure, climate, &c." And in 

 the first volume of their transactions will be 

 found several valuable essays on the subject, 

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

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

 illustrating the value of the study of plants to 

 the cultivator. 



The definition of a plant to a superficial ob- 

 server may appear easy; but those who ha\e 

 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 emit 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 

 (Dionsca musdpula) 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 pudica] shrink from the 

 slightest touch. Oxalis sensitive! and Smithia 

 sensitiva are similarly irritable ; as also are the 

 stamens of the flower of the barberry. One of 

 this tribe (Hcdysarum gyrum) 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 (Apocynnm androtsemifo- 

 Hum'], 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- 

 tability, we can pursue that path of the science 

 no farther. 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, ani 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 1 ? 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 sho^ 

 that it had pervaded the whole. Let a fe\ 

 more hours pass auay, 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 reducgd 

 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 

 serves to steady or fix the plant firmly in a 

 commodious situation and position. Roots are 

 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 flowerr 

 during a succeeding year, as wheat. Perennia' 

 roots belong to such plants as live for severa* 

 years. All plants are considered as biennial* 

 that are raised from seed one year, arid flowei 

 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 

 (Laval era 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 odbrald), 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 (Tropseotum), 

 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 

 clown 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 



