With regard to bottom-beat, it should be in imitation of the heat of the tropical soil ; and this varies even less than the temperature of a tropical atmosphere. The mean temperature of the earth is rally supposed to be somewhat higher than the mean of the atineeplitre, owing to the greater capacity of the soil for retaining caloric. The discrepancy, however, cannot be great; and if the mean atmosphere, temperature at the equator be from 80' to 84', as has been ascer tained from numerous observations, the temperature of the soil, it may be presumed, will not average lower ; nor will It be many degrees higher where moisture sufficient for vegetation exists, as is generally the case in Wends; although on continents it becomes ea great as to reduce the soil to a desert. The temperature of the earth a foot below the surface, in New Granada, is 85' during summer, according to a cotrespondent of Mr. Illy ('Oard. Mag.'); and this degree of heat will be found a very good medium for the roots of the pine-apple.' Bottom•heat then should never be allowed to fall below 75", nor rise higher than 90'.
Pine-ripples can be raised from seeds, but In England this is rarely done except for the purpose of procuring varieties. They are pre irrigated usually from suckers. Formerly the crowns were need, but the suckers are found to be more early productive. The soil in which they are planted requires to be rich. A fresh yellow loam, strong, but by no means of a binding nature, with which is mixed a quantity of cow-dung, will answer very well. The pots require to be well-drained, and over the drainage some pieces of turf may be placed. Manure water. made by steeping sheep's-dung or oow.dung, is occasionally applied, care being taken that it be properly diluted. If the plants are found not to be thriving, they may be shifted, without hesitation, at any period of their growth.
It is very important that a perfect drainage be at all times main taiued. When pots are plunged in tan, the worms Are apt to close the holes in the bottom of the by their excretions ; or a stoppage may occur in consequence of the pressure of the pot upon the tan when it wastes and becomes capable of being rendered compact. Front whatever cause the defect proceeds, a good preventive may be easily effected by simply plunging an empty pot, with its mouth downwards, and on this placing the bottom of that containing the plant, closing the tan round the sides of the latter in the usual way. If at any time the tan should become too hot, it may be partially removed from the Aides of the pot.
Moisture is essential for the growth of the pine-apple. The con dition of the soil in the pots trill of course indicate whether water should be applied or withheld. But in summer the atmosphere should be kept moist by syringing, particularly before shutting lip at night. No water should on any account be used of a temperature many degrees lower than that of the soil in the pots where the plants are growing; it should not, in short, be applied lower than 75 , and 80' will prove a good medium. When the fruit is ripening off, moisture
of course should be withheld ; and in damp cloudy weather in winter, when it is an object to restrain rather than promote growth, they should be kept rather dry than otherwise. Moisture Will not prove Injurious when it is accompanied by a sufficiently high temperature and a due share of light. The mode of heating by means of hot water pipes is undoubtedly the best for pine-stoves; and steam from the boiler should be at command, so that it may be introduced to the interior of the house as occasion requires.
Pine-apples may be grown under various modes of treatment, Instead of being confined in rote, they are sometimes planted in a bed of soil. This has been found to answer very well where good drainage was secured, and where a proper degree of bottom-heat could be applied. They have also been grown in pots placed on shelves or on sand; this mode, however, has not proved fully successful, for the roots are subjected to vicissitudes consequent not only upon the variations in the temperature of the atmosphere of the house, but also its hygrometrical conditions.
A principal cause of failure in the cultivation of the pine-apple appears to have arisen from the idea that the plants will bear a much lower degree of temperature than that above pointed out as being natural to them. They will apparently do so; but although the plants may continue to have a healthy appearance, yet experience proves that their vital energy is interfered with, and their powers of organisation diminished, its is continually indicated by the fruit-etern being sent up with only a few imperfect pips. The stagnation of water about the roots from defect of drainage, too much heat and moisture, or too much heat and dryness, or checking the plants by cold in order to bring them to a fruiting condition, instead of forwarding them naturally to that state, are other sources of failure on the part of cultivator*. With regard to the last, the only method that ought to be taken to bring on the time of fruiting is to inapt/mate the sap, and to augment the amount of secretions by gradually withholding moisture and increasing the temperature, at the same time admitting a little more air than usual ; and after this, by the sudden application of a brink temperature with more moisture.
To richly manured evil the largo size of the pine-apples produced In England may be attributed ; and to the means that cultivation under glass affords of progressively inepiwiating the juices towards the period of ripening, may be ascribed the superiority of the fruit to that pro dnced in countries where the plants are indigenous, an alluded to under Anansans,satira, in Nay. liter. Div.
Pine-apples are now cultivated to a large extent in the Bahama /elands for the English market.
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