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Page:Popular Science Monthly Volume 9.djvu/431

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OUR COMMON MOULDS.
407

In Fig. 9 is given a mould which makes its home on decaying herbage, and is found to perfection in old waste-heaps where weeds and other green matter have been deposited. So common is it, that a culture is more a matter of convenience than necessity. The fruit-stalks are upright, considerably branched at the top, with the spores borne in bunches at the ends of the filament. At a is a much enlarged view of one of these naked heads of spores, and another where the spores have mostly fallen away. As the fruit-stalks grow old they break down in every way, giving the appearance of a forest over which a tempest has passed.

Of the black moulds Fig. 10 shows a common and very simple representation. It grew as a sooty coating on a culture made of sliced raw potatoes. It is so very simple that any space taken for description seems unnecessary. The black spores are nothing more than portions of single or branched filaments cut off in a very regular manner.

Fig. 10.Fig 11.

In Fig. 11 is given the general structure of a large number of related moulds which grow wherever they can get a foothold. The drawing was made from one found on some turnip-roots left upon the ground over winter. Like many others, it forms an olive-brown, velvety coating of considerable thickness; and, because of their low habits and inobtrusive nature, they pass readily for dirt or decay, and are seldom noticed. They are the lowly forms which some of the highest of the fungi assume in passing through one stage of their polymorphic existence.

A score of other species of moulds deserve mention here which are found on various substances either forced under the bell-jar, or growing naturally; but we know how unattractive such descriptions would be without accompanying figures, and therefore pass them by.