Book I. ANOMALIES OF VEGETABLE DE VELOPEMENT. 215 



shoots in the following spring ; and thus the bud is to be regarded as forming, not only the cradle, but also 

 the winter quarters of the shoot, for which its coat of tiled and glutinous scales seems admirably adapted. 

 It is found chiefly in the extremity, or on the surface of the young shoot or branch, and but rarely on the 

 stem, except it be at the collar where it produces suckers. It is also generated for the most part in the 

 axils of the leaves, as may be seen by inspecting the annual shoot of almost any tree at random: but it is 

 not universally so ; for to this rule there exists a curious and singular exception in the bud of the 2>la- 

 tanus, which is generated in the verv centre of the base of the foot-stalk, and is not discoverable till after 

 the fall of the leaf. But how are the buds formed which are thus developed? Malpighi thought they 

 were formed from the pith or cellular tissue, which Grew regarded as viscera destined for the elaboration 

 of the sap and protrusion of future buds. Du Hamel thinks the exterior scales of the bud originate 

 in the interior part of the bark, and Knight relates an experiment from which he thinks it follows that 

 the buds are formed from the descending proper juice. But whatever may be the actual origin of the 

 bud, it is evident that its developement does not take place except through the medium of the proper 

 juice, which has been elaborated in the leaves of preceding buds, and originally in those of the plumelet, 

 as the young bud does not make its appearance till the leaves of the preceding buds have expanded, and 

 will not ultimately succeed if deprived of them too soon. 



1585. The bark, it is probable, performs the same functions as the leaves in the early state of the buds, and 

 occasionally in all states. Otherwise it would not be easy to account for the growth of cactuses, euphor- 

 bias, some apocyneous plants, &c, which are all destitute of leaves. In fine, the bark may be compared 

 to a universal leaf, with one surface only. ^London Ency. art. Bot.) 



1586. Bulbs are so very similar to buds both in their origin and developement, as to require no specific 

 investigation. 



1587. The leaf. When the leaves burst from tl e expanding bud, and even long before that period, as 

 may be seen by the dissection of the bud in the winter, they are complete in all their parts. Hence it is 

 obvious that the leaf, like the voung shoot, effects its final developement by means of the introsusception 

 of new particles throughout the whole of its dimensions ; and vet this law of developement is not common 

 to all leaves whatever, lor the leaves of liliaceous plants extend chiefly at the point of their junction with 

 the bulb. The effect, perhaps, of their peculiarity of structure, in being formed of parallel tubes which 

 extend throughout their whole length, without those transverse and branching fibres that constitute what 

 are called the nerves of the leaves of woody plants. 



1588. Thrjimver and fruit. When the Mower bursts from the expanding bud, and even long before that 

 period, it is already complete in all its parts, as may be seen also by the dissection of the bud in 

 winter. Liniueus represents the pistil as originating' in the pith, the stamens in the wood, and the 

 corolla and calvx in the inner and outer bark respectively : but this account of their origin, though ex- 

 tremely plausible at first sight, will not bear the test of minute examination, being contradicted by the ana- 

 tomy of the parts themselves; particularly in the case of compound flowers. Knight, in investigating the 

 organisation of the apple and pear, endeavoured to ascertain the origin of the several parts by tracing the 

 organs of the fruit-stalk to their termination In the fruit-stalk he thought he could discover thepith, the 

 central tubes, spiral tubes, and tubes of the bark, together with its epidermis : and in tracing them to their 

 termination, he thought the pith seemed to end in the pistils; the central vessels in the stamens, after 

 diverging round the core and approaching again in the eye of the fruit; and the bark and epidermis 

 in the two external skin*. Hence he infers that the flower is a prolongation of the pith, wood, and 

 bark. A question of some considerable importance has arisen out of this subject : does the flower or 

 fruit elaborate sap for its own developement, or is it supplied with nourishment from the leaf? By 

 placing small branches of the apple, pear, and vine, with blossoms not expanded, in a decoction of logwood, 

 Knight found that the central vessels were coloured by the decoction. By means of a similar experiment 

 on the same subjects after the fruit was formed, the colouring matter was traced through the mass of the 

 fruit to the base of the stamina. And hence it appears that the flower and fruit do possess the power 

 of elaborating sap for their own developement. Knight infers from the foregoing data, that the blossom 

 is nourished from the alburnum, by means of the mingling of the proper juice, which the alburnum may 

 be supposed to contain, with the sap in its ascent. 



Sect. V. Anomalies of Vegetable Developement. 



1589. A deviation from the general laivs of developement is occasioned by the interven- 

 tion of some accidental cause ; or of some cause operating permanently in certain sub- 

 jects. Hence the anomaly may regard the developement either of an individual or a 

 species, and may occur either in the root, stem, branch, leaf, bud, flower, or fruit, ac- 

 cording to the circumstances in which it is placed ; or it may affect the habit, duration, 

 or physical virtues of the plant. 



1590. The root. According to the general laws of vegetable developement, plants of 

 the same species are furnished with the same species of root, not producing at one time 

 a woody or fibrous root, and at another time a bulbous root : and yet it is found that 

 there are cases in which changes of this kind do occur. If part of the root of a tree, 

 planted by a pond or river, protrudes beyond the bank so as to be 

 partially immersed, it divides at the extremity into innumerable 

 ramifications, or sends out innumerable fibres from the surface, 

 which become again subdivided into fibres still more minute, and 

 give to the whole an appearance something resembling that of the 

 tail of a fox ; and it has accordingly been denominated by Du 

 Hamel the fox-tail root. (Jig. 189.) 



1591. The root of the Yhlium pralt'nse, when growing in a moist soil, which 

 it naturally affects, is uniformly fibrous ; but when growing in a dry soil, where 

 it is also often to be found, it is furnished with a bulbous root. The same is 

 the case with the y/lopecurus geniculatus ; which, when growing in its native 

 marshes, protrudes a fibrous root, though, when growing in a very dry situation, 

 as on the top of a dry wail, it is found to be furnished with an ovate and juicy 

 bulb. This anomaly also seems to be merely the result of a provision of nature 

 by which the plant is endowed with the capacity of collecting a supply of jf± 

 moisture suited to existing circumstances, and hence of adapting itself to the 

 soil in which it grows. 



1592. The roots of Utricvlaria m'mor, which consist of a number of slender 

 and hair-like filaments, exhibit the singular anomaly of being furnished with a 

 multitude of small and membranous bladders, each containing a transparent 

 and watery fluid, and a small bubble of air, by means of which the plant is kept floating in the water. 



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