CH. X] 



THE SLIME-MOLDS 



413 



hibits active streaming and other movements, whereby it 

 creeps over the substratum like an animal, e.g. the Amoeba. 

 It becomes quiescent in times of dryness, and renews its 

 activity during humid intervals. Ordinarily it keeps away 

 from light, and hence lurks in crevices, or under damp objects. 

 But when about to produce spores, the plasmodium moves 

 out from the shelter, rises to the summit of the object be- 

 neath which it formerly lay, and there proceeds to convert 

 its entire substance into 

 sporangia, one or a cluster, 

 containing asexual spores. 

 The sporangia, easily visible 

 to the naked eye, have 

 usually a supporting stalk, 

 a firm wall, and an inte- 

 rior lacy-delicate framework, 

 called the CAPILLITIUM (Fig. 

 283). This capillitium, by 

 its swelling and hygroscopic 

 movements, pushes out the 

 spores, which are then re- 

 moved by the wind. It 

 differs greatly in form 

 the different species, and plt 

 often, like the sporangium wall, is brilliantly colored. 

 Thus the sporangia exhibit a diversity and beauty of which 

 the plasmodia contain little suggestion. In the formation 

 of the spores occur certain nuclear fusions which suggest 

 fertilization, the lowest traces thereof known among plants. 

 The spores possess thick cellulose walls, and are true rest- 

 ing spores. After dissemination, they germinate in water and 

 form unicellular free-swimming swarm spores, which recall 

 the Flagellates. They swim, about freely for a time, living 

 saprophytically ; then they come to rest and form amceba- 

 like bodies, which multiply by fission. Ultimately they 

 creep together in groups, and these into larger groups, until 



FIG. 282. Plasmodium of a Myxo- 

 mycete ; X f 

 in The flower pot stood in a damp shaded 

 (Drawn from a photograph.) 



