The use of the ascending sap in the vegetable economy is the last subject which we shall consider in this article. On a future occasion we shall endeavour to show that it is out of the ascending sap that the descending or elaborated sap is chiefly formed; but besides this utility of the ascending sap, as the source of the descending sap, the former has special functions of its own to perform. If we inquire what period of the year is the ascending sap in greatest quantity, we shall find it to be during the spring season. Now, this is the time when the buds become pushed out into branches, and the young leaves peep forth: the roots also during this season increase in thickness. Another means which we possess of ascertaining the uses of this sap, is by protecting plants from the influence of light: in total darkness no elaborated sap is ever formed; therefore, whatever vegetation may then take place, must be solely at the expense of the ascending sap. Under such circumstances the plant becomes very succulent, its stems grow to a great length, no vegetable fibre can be detected in its substance, its colour is blanched, it possesses no bitter or aromatic properties, and it does not develope flowers. Potatoes growing in a dark cellar, or celery protected from the light, by earth heaped around its foot-stalks, will afford familiar examples. These considerations lead us to the belief that out of the ascending sap is formed the fleshy part of vegetables, which, by its production, increases the length of the stem, and the thickness of the roots. In our next article we will describe the most remarkable properties of the ascending sap. T. A. MEN OF GENIUS. Have any of our friends any persons of this description amongst the young men of their acquaintance? We think they must, for they are very plentiful: they are to be found every where. We ourselves know somewhere about half a dozen of one kind or other; and it is of these different kinds we purpose here to speak. Before doing this, however, let us remark, that the sort of geniuses to whom we allude are to be found amongst young men only: for, generally speaking, it is only while men _are_ young that they are subject to the delusion of supposing themselves geniuses. As they advance in life, they begin to suspect that there has been some mistake in the matter. A few years more, and they become convinced of it; when, wisely dropping all pretensions to the character, they step quietly back into the ranks amongst their fellows. It is true that some old fools, especially amongst the poetical tribe, continue to cling to the unhappy belief of their being gifted, and go on writing maudlin rhymes to the end of the chapter. But most men become in time alive to the real state of the case, and, willingly resigning the gift of genius, are thankful to find that they have common sense.