Page:Popular Science Monthly Volume 9.djvu/424

400 color; but soon they begin to grow darker, their contents shaping into little round bodies, which when ripe are dark-colored and fill the capsule to repletion. These little bodies thus produced in vast numbers in the swollen ends of these vertical threads are termed spores, and answer the same purpose for moulds that seeds do for



plants. From the same base several of these capsules are produced, varying in age from threads with their tips little swollen, to the tall and aged ones which have ripened and scattered their spores. This mould has much the habit of the strawberry-plant, throwing out runners or stolons, which take root and in turn become new plants to increase and continue the species. In the culture we have often 6een this mould hanging from the bread on the rack to the plate below, a distance of four or five inches, with here and there the stolons with their fruit-clusters hanging in mid-air (Fig. 1).

The fruiting which has been described is asexual, and the spores thus formed can be likened to the bulbs in the axils of the leaves of the tiger-lily and other reproductive bodies in flowering plants which do not result from a fertilized ovule. Several trials were made to cultivate the sexual fruit of this plant, but without success; another member of the same genus (Mucor Syzygites), which grows on decaying toadstools, produced them under the bell-jar in large quantities. When this plant reaches the proper stage of development for the formation of its sexual fruit, the tips of various filaments become noticeably swollen. Two of such enlarged ends grow toward each other and finally meet by their extremities, or rather by the blending of the processes which each cell puts out, thus forming at first a small cell between the two united filaments. As maturity is reached, this zygospore