Fig. 3, Plate V., is the capsule of the Jungermannia, one of the liverworts, showing the “elaters” bursting out on every side, and scattering the spores. Fig. 4 is a single elater much magnified, showing it to be a spirally coiled filament, that, by sudden expansion, shoots out the spores just as a child’s toy-gun discharges the arrow. Fig. 5 is a part of the leaf of the Sphagnum moss, common in fresh water, showing the curious spiral arrangement of secondary fibre which is found in the cells, as well as the circular pores which are found in each cell at a certain stage of growth. Just below, and to the left hand, is a single cell greatly magnified, in order to show these peculiarities more strongly. Fig. 8 is part of a leaf of Jungermannia, showing the dotted cells. Fig. 6, Plate V., is a part of a rootlet of moss, showing how it is formed of cells elongated and joined end to end. On the common mare’s-tail, or Equisétum, may be seen a very remarkable arrangement for scattering the spores. On the last joint of the stem is a process called a fruit-spike, being a pointed head around which are set a number of little bodies just like garden-tables, with their tops outward. One of these bodies is seen in Fig. 40. From the top of the table depend a number of tiny pouches, which are called sporangia; these lie closely against each other, and contain the spores. At the proper moment these pouches burst from the inside, and fling out the spores, which then look like round balls with irregular surfaces, as shown in Fig. 40, _c_. This irregularity is caused by four elastic filaments, knobbed at the end, which are originally coiled tightly round the body of the spore, but by rapidly untwisting themselves cause the spore to leap about, and so aid in the distribution. A spore with uncoiled filaments is seen at Fig. 40, _b_. By breathing on them they may be made to repeat this process at will. Fig. 36 is a common little sea-weed, called Ectocarpus siliculósus, that is found parasitically adhering to large plants, and is figured in order to show the manner in which the extremities of the branches are developed into sporangia. Fig. 37 is a piece of the common green laver, Ulva latíssima, showing the green masses that are ultimately converted into zoospores, and by their extraordinary fertility cause the plant to grow with such rapid luxuriance wherever the conditions are favourable. Every possessor of a marine aquarium knows how rapidly the glass sides become covered with growing masses of this plant. The smaller figure above is a section of the same plant, showing that it is composed of a double plate of cellular tissue. Fig. 41 is a piece of purple laver or “sloke,” Porphýra laciniáta, to show the manner in which the cells are arranged in groups of four, technically named “tetraspores.” This plant has only one layer of cells. On Plate V. may be seen a number of curious details of the higher algæ.