In considering, then, aspect as regards sun and heat, I may observe that it is impossible to exaggerate the importance of taking into account the immense variation in temperature on the different exposures. For the effect that the sun's rays have on certain aspects in heating the soil and drying up the plant, are such as would be extremely difficult to believe, had the facts not been verified by competent observers, and with the aid of the thermometer. And as regards northern and southern slopes in particular, we shall find that the difference between one exposure and the other is just what constitutes the difference between green and dried grass, and between leaves luxuriantly green and leaves dry and withered. And that the first is literally true may be seen by anyone in the months of January and February, for in these months you will see grass on northern aspects green, and, comparatively speaking, fresh, while, even in a valley sheltered from drying winds, the grass on the southern slopes is completely withered. And you will see an equally striking difference in the coffee plants--those on the northern slopes full of health and life, while those on the southern ones are yellow, dried up, and sickly. Even in parts of the district where coffee will not thrive without a considerable amount of shade, you will always find the plants thrive well (with little or even none) on a northern bank, and look much better than on a moderately shaded southern bank. Nor in the nursery is the effect of aspect at all less striking. A nursery on a northern slope will require far less water, and far less shade over the plants, than one with a southern exposure. But the late Mr. MacIvor, superintendent of the Government Cinchona plantations on the Nilgiri hills, has tested the value of northern and southern aspects in a way which accurately judges their respective values. He accordingly tells us that, "The reason why a northern exposure in these latitudes is beneficial is from the fact that it is much more moist during the dry season than a southern aspect, because the sun's declension is southerly during the dry and cloudless season of the year, and thus, on the northern slopes, the rays of the sun do not penetrate and parch the soil. A northern aspect has also the advantage of preserving a much more uniform temperature than a southern aspect, because the excessive radiation and evaporation in the southern slopes greatly reduces the temperature at night, while in the day they are heated to excess by the action of the sun's rays striking the surface nearly at right angles. The practical effects of aspect on the plants are so great that they cannot be overlooked with impunity, and, in order to impress this on the minds of all those who may have the selection of localities for cinchona cultivation, I may mention that the difference of temperature is almost incredible; for example, at this elevation (probably