It is indead wonderful how easily the roots of plants and trees bore through hard, impacted soils in search of' nourishment. They use lor this purpose a sort of awl, of immense power, situated at the end of the root, and oapable, with the aid of the other root inachinery, of thrusting aside heavy weights and getting through almost all obstructions. Yet the awl consista only of a mass of microscopio absorbent cells formed by protoplasm or vegetable mucus- the fluid in which the vital action is first set up. The roots of the elm and the maplo will bore through the hardest soil of walks or stréets, enter drains, twino about water pipes, and penétrate the seams of stone and brick structuros. The roots of some plants have been known to pasa through eighteen inches of solid brick-work, and make their appoarance in a wine-cellar below. Plants have a vast power in overcomiug obstacles when foraging for food, and will penétrate through a clay bank toreach the desirud foraging ground. The first year's experieuce of the governraeut in the sale of postal cards has proven that they are far moro popular as a means of cheap communication than the postoffice authorities had anticipated they wonld be. The estímate by the dopartment of the nuinber that would be required the first year was 100,000,000, while the number furuished was 113,662,000, which would have been largelv increased if there had not been a delay in furnishing them on the part of the printers during the first three mouths after thoir introduction. The following is a list of sixtocn cities in which the greatest number was sold, and in which, it will be seen, Detroit stands the twelfth : New York, 12,500,000 ; Boston, 6,102,000 ; Chicago, 5,200,000 ; Philadelphia, 5,000,000; Ht. Louis, 3,600,000 ; Oincinnati, 2,400,000; Baltimore, 1,875,000; Tiutfalo, 1,500,000,; San Francisco; 1,400,000; Pittsburgh, 1,300,000; Washington, 1,175,000; Detroit, 1, 150,000; ijouisville, 1,000,000; Cleveland, 600,000 ; Milwaukeu, 00,000 ; Indianapolis, 720,000.- Vree Preu.