Closely related to _Vaucheria_, but not quite so common, is the curious little plant known as _Botrydium Granulatum_. Like our previous example, it is a one-celled plant and herein lies its interest. When find a specimen growing by a pond, we shall notice a green bladderlike portion, not more than 1/6 inch in diameter, which projects above the ground. Below ground, if we pick the soil away carefully we may observe a number of colourless, branched structures which do duty for roots. The bladder and underground portions are hollow, being lined in the case of the former, with a network of chlorophyll beautiful to observe under the microscope. _Botrydium_ usually increases by buds which form on the green bladder, break away and grow into new plants. Should the level of the water in the pond rise, and the little plant become submerged, it splits up into a number of small bodies, each provided with a minute whip-like organ, with which they swim rapidly ashore where they develop into new plants. In dry weather the plant forms a number of little cells each one surrounded by a firm cell wall. When moisture comes again these little cells give rise to structures which will grow into new plants. Surpassing even _Drapernalda Glomerata_ in point of beauty, is the “water-net,” _Hydrodictyon Reticulatum_, but it is not nearly so common, being confined to ponds in the South and Midlands. When full grown it hardly comes under the heading of a microscopic object, for it may measure as much as six inches in length. This remarkable pond plant consists of an open network of green filaments. Apart from its striking appearance the most remarkable thing about the “water net” is its rapid growth. Carpenter, a noted microscopist says:--“The original cells of which the net is composed measure one-two thousand five hundredth part of an inch in length but in a few hours they grow to one-twelfth of an inch or 1/3 of an inch in length. We often hear people remark that they can see plants grow, but their statements are not literally true; in the case of the ‘water net’ it is actually possible to see the growth.”