June 2, 1884.] 



THE TROPICAL AGRICULTURIST. 



86s 



modate themselves to new circumstances, die out. On 

 some such principles, probably, depends the fact that the 

 gardener can grow certain plants without difficulty, while 

 others doty all his efforts. But to descend from the region 

 of speculation to that of practice, we may pouit out that 

 the internal conformation of plants sometimes offers as good 

 hints to the cultivator as to the conditions under which 

 certain plants may be expected to thrive as the more easily 

 observed external appearances do. 



Ey way of illustration we may mention the presence in 

 the leaves of certain plants of what are termed palissade- 

 eells. These are oblong cells, arranged vertically, that is, 

 at right angles to the surface of the leaf. Their form and 

 direction maybe imlicated thus ||||i!||, the ordinary leaf- 

 cells being more or less globular or branching, or, if elong- 

 ated, then elongated horizontally in a direction parallel to 

 the surfaces of the leaf. The term " palisaade-cells," then, 

 very well OKpresses the form and arraLgement of a cert- 

 ain class of cells packed closely together, like tho wooden 

 rails of a park fencing. A very low power of the micros- 

 cope is sufficient to allow these cells to be seen, and in 

 some cases an ordinary pocket lens, if of tolerably high 

 magnifying power, is sufficient to enable them to be seen. 

 These palissade-colls are usually filled with " leaf-green," 

 or chlorophyll. 



We cannot hero pursue the subject from tho point of 

 view of tho anatomist or physiologist, it must suffice to 

 point out the practical deductions which are insisted on by 

 Stahl, Vesque, and other students of this particular structure. 

 When a gardener, says M. Vesque, in substance, receives 

 a new plant of imperfect or unknown history, he does not 

 pay much hoed to .systems of classification, as a botanist 

 would do, for they afford him little help. He judges by 

 the external appearances of the plant what is likely to be 

 the appropriate treatment, and so, for instance, he sub- 

 mits to the same general comlitions Stapelias and Aloes, 

 Agaves and Mesembryanthemums, and so forth — plants, in 

 fact, whose " habits " and requirements are the same, whose 

 adaptive characters, that is, are identical, although their 

 more purely hereditary pecuharities are widely different. 

 In the case of succulent plants, such as those just men- 

 tioned, the matter is easUy determined ; but in those cases 

 where the exterior appearance gives no indication of the 

 habit and requirements of the plant then a microscopic 

 examination must be made, and this will enable' the ob- 

 server to say with something like certainty whether the 

 plant naturally grows in the sun or the shade — whether 

 its internal structure is such as to allow of free or of 

 relatively little transpiration — whether it is likely to de- 

 mand frequent and coi>ious waterings, ov whether it is 

 capable, of living long without any. We may give a few 

 illustrations. If the palissade-cells are abundant and wel- 

 markud, the probability is that the plant requires a proe 

 portionate amount of exposure to hght; if, on the othe- 

 haud, the palisades are scanty or not present, the inference 

 is that tho plant requires to be grown in the shade. Be- 

 tween these two extremes is a group of plants of variable 

 and inconstant nature : such plants obviously are enabled 

 by Nature to adapt themselves more or less successfully 

 to different conditions. 



In the case of moisture, the subject may be divided into 

 the discus.sion of the arrangements for, in the first place, 

 the supply of water ; and, secondly, for its retention and 

 stoiagc. Indications as to the sujiply. great or little, may 

 be gathered from the thickness of "the cuticle, and the 

 number and position of the pores or stomata. 



As to the faculty of storage, that may be judged of from 

 tho nature of the cpiderm or skin beneath the cuticle, 

 the abundance of cellular tissue— that is, the succulence of 

 the leaf, and other characters. The first set of characters 

 supply liints as to the absolute quantity of wa-ter required ; 

 for instance, the thinness of cuticle and abundance of 

 stomata would naturally suggest frequent and copious water- 

 ings ; tho second set of characters suggests the aljundanee 

 and frequency of water, whether little and often, or a large 

 quantity less often. Plants whose thick rinds indicate a 

 relatively little amount of transpiration naturally require 

 a hotter temperature and a fuller exposure to light than 

 others. 



A plant with small pores or stomata transpires less than 

 one with large or with numerous pores. Hairs on the sur- 

 face check transpiration, spongy construction of the leaf is 

 UU 



also an indication of relatively littlo transpiration. Obvi- 

 ously, the more fleshy the plant the less need there is for 

 watering frequently. 



Hard woody cells, such as those which constitute the 

 grit of a Pear, and which serve as a .sort of skeleton to 

 support the tissues, are taken by M. Vesque to indicate 

 that tho plant is exposed to bright smiliglit and occasional 

 drought, as Proteas, &c., or to occasional excessive losses 

 of water, and indicate the necessity for copious watering 

 at intervals, as in the case of succulent plants. 



Pursuing his subject M. Vesque goes on to show how 

 the epidermal cells, or those sub-adjacent to them, in some 

 cases act as reservoirs for water ; and how in tho tissues 

 of some leaves may be found other structures having a 

 similar office, so that tho thick rind, tho deficiency of stom- 

 ata, the dense hairs with which plants growing in dry 

 places are provided, indicate the quantity of water 

 which traverses the plant, while the reservoirs for water 

 furnish indications as to the frequency of "wateiiug and 

 the length of interval between the operations. 



The intelhgent observer, adds I\I. Vesque, will know how 

 to avail himself of the indications presented to him, which 

 will be varied and combided in a thousand different ways, 

 but from flhich he vrill be enabled with accuracy and judg- 

 ment to regulate the delicate operation of watering. 



We have no doubt whatever that M. Vesque is on the 

 right track, but we fear it will be long before our young 

 gardeners will avail themselves of the lielp of the micros- 

 cope rather than of the rough-and-rendy me.T euros that 

 they are accustomed to practise. In any case it will be 

 admitted that there aro few operations in practical garden- 

 ing which aro carried out with less intelligent judgment 

 than is watering, and any means which may serve to ob- 

 viate this will be a boon to head gardeners. 



Lastly, we may mention that we have put M. Vesque's 

 notions to a partial test with reference to the leaves of 

 Orchids, which present remarkably great variations of struct- 

 ure, and in some cases of great interest. AVe have ex- 

 amined one or two dozen species, with the general result 

 of confirming 11. Vesque's notions, or, at least, of satisfy- 

 ing ourselves that " there is something in them." On an- 

 other occasion we may speak more fully on this point. — 

 Gardeners' Chronicle. 



PADDY CULTIVATION. 



TO THE EDITOR OF THE "EXAMINER." 



Dear Sir, — In your issue of the 8th instant appeai s the 

 excellent paper of Mr. Weerackody on Paddy Cultivation, 

 as read before the Agi-icultural Association. It is a sign 

 of the times that intelligent interest is now being paid to 

 the cultivation of this food product. If all landowners 

 amongst the Sinhalese gentry took as intelhgent an interest 

 in paddy cultivation as ]\Ir. Weerackody, and published 

 the results of their experiments rice-growing will not be, 

 as now, an industry that barely paid its way. 



Mr. Weerackody seems to have had three olijects in vievi 

 in the experiments he undertook. The first two, to decide 

 whether transplanting was better than sowing broadcast, 

 and second the effect of manure, I am inclined to think, are 

 sufficiently apparent to any intelligent observer to obviate 

 the necessity of making experiments to determine. How- 

 ever, it is as well that they were decided by personal investig- 

 ation. The third reason, to decide between the cost of 

 cultivation on the share system by Goiyas and by hired 

 labour — I confess was laudable, as it is an open question 

 and ono in which the decision is invariably given to the 

 share system, by those wlio have tried both. Whatever 

 intiuence Mr. Weerackody's figiu-es and inferences may have 

 had on others, they have not convinced me that it is cheaper 

 to cultivate with hired labour, for I question his figures. 

 To begin with, I believe Mr. Weerackody sowed bis fields 

 too thick, if he used, as he says, 6 busl els of paddy for 

 two acres. My idea always was — I may be mistaken — that 

 an acre represented two bushels sowing-extent. Even that 

 is too much for fields with a rion soil, and the over-crowding 

 of tho plants acts injuriou.sly on their crop-bearing powers. 

 Then Mr. Weerackody does not tell us whether the three 

 plots experimented on were of equal extent, and the soil 

 nearly as possible the same. For, anyon e who carefully 

 notices a paddy field will have foiuul that fjie fertility. 



