326 THE AMERICAN MONTHLY [Nov 



ures described are not in the two cases homologous ; only 

 analogous. The sporangium of the Slime-mould exhibits 

 usually a distinct peridium, or outer limiting wall, which 

 is at first continuous, enclosing the spores and their at- 

 tendant machinery, but at length ruptures, irregularly as 

 a rule, and so suffers its contents to escape. The perid- 

 ium may be double, varies in texture, color, persistence, 

 and so forth, as will be more fully set forth in the sev- 

 .eral specific descriptions. The peridium blends with the 

 hypothallus below when such structure is recognizable, 

 either directly, when the sporangium is sessile, or by the 

 intervention of a stipe. Associated with the spores in 

 the sporangium occurs the capillitiuin. This consists of 

 most delicate thread- or hair-like elements, offering the 

 greatest variety both in form and structure. The threads 

 composing the capillitium are not to be regarded, even 

 when free, as cells, nor even of cellular origin ; they are 

 on the other hand, in such a case, simply shreds and strands 

 of the original plasmodium, portions that have not been 

 used in the formation of spores, and are accordingly mod- 

 ified in such wise as to be useful in spore-dispersal. The 

 capillitium threads may be solid or hollow, they may oc- 

 cur singly or be combined into a net, they may be terete 

 or flat, attached to the peridial wall or free, simple or 

 adorned with bands or spires and knobs in every variety, 

 uniform or profusely knotted and thickened at intervals, 

 and burdened with calcic crystals. 



The germination of the spores ensues closely upon their 

 dispersal or maturity and is unique in many respects. The 

 wall of the spore is ruptured and the protoplasmic con- 

 tent escapes as a zoospore indistinguishable so far from 

 an amoeba. The amoeboid zoospore is without cell wall, 

 changes its outline, and moves slowly by creeping or flow- 

 ing from point to point. At this stage many of the spores 

 assume each a flagellate cilium, and so acquire power of 

 more rapid locomotion. The zoospores, whether ciliate 



