28 Minnesota Plant Life. 



dust which can be shaken out upon the hand or upon a piece 

 of paper. This brown dust, under the microscope, is seen to 

 consist of innumerable tiny spheres, the spores of the plant. If 

 the spores be placed in water, after a time their shells break and 

 out of each comes a little mis-shapen drop of jelly-like substance, 

 which oozes away with a slow and viscid movement. If several 

 of these tiny l)its of jelly find themselves close together — per- 

 haps after a rain upon the bark of some rotten log — they crawl 

 towards each other and fuse into a common patch. The patch 

 then moves imperceptibly over the wood, increasing in size as it 

 extracts nourishment from the decayed material. Sometimes 

 the jelly-masses grow to the size of a man's hand. A common 

 sort is found in tan yards and often upon railway ties resembling 

 very much a piece of ordinary thin jelly and generally cov- 

 ered with a sulphur-colored powder. After the jelly-mass has 

 increased in size to a certain point it breaks up into little clusters 

 which afterwards develop fruit-bodies more or less like the 

 brown plumes spoken of above. 



Another kind of slime-mould crawls up the stems of various 

 plants in meadows and deposits itself upon the leaves in little 

 foam-patches looking very much like drops of spittle. There 

 are some insects which make similar s])ittle-masses on leaves and 

 an expert investigation is necessary to determine whether such 

 objects are insect products or the plant bodies of slime-moidds. 



Some slime-moulds have the power of incrusting their tiny 

 fruit-1)odies with lime \\hich they extract from their soil or from 

 rain-water that falls upon them. Such forms are often observed 

 in Minnesota upon dead wood, or fallen leaves, generally in 

 moist shady ])laces in the deep forest. Sometimes the fruit- 

 bodies are almost round, resembling the familiar [mIIs of the 

 homeopathist. In other species they are worm-like, coiled like 

 loose snail-shells, but very nuicli smaller, yet not so small that 

 they cannot easily be disco\ered if searched for in the places 

 that they have chosen. A few slime-moulds will be encountered 

 among mosses, forming little brown scurfs upon the moss tuft 

 or displaying themselves as yellowish patches around the bases 

 of the leaves. None of these plants have any economic import- 

 ance. The most conspicuous one in Minnesota occurs upon 

 dead logs as pink, hemispherical bodies, about the size of the 



