6 INTRODUCTORY 



great 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; probably, as would appear from the researches of 

 Strasburger and Harper, all forms of capillitial threads arise in con- 

 nection with vacuoles in the protoplasmic mass. "Whether the 

 thread is hollow or solid, simple or branched, free or connected with 

 the peridium or a columella, — these are entirely secondary condi- 

 tions, depending on the extent and form of the vacuoles." ^ They 

 may occur 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 par- 

 ticles. In many cases, the capillitium contributes materially to the 

 dispersal of the spores; in others, it doubtless contributes mechan- 

 ically to the support of the peridial wall, and renders so far per- 

 sistent the delicate sporangium. For more exact description the 

 reader is again referred to the specific delineations which follow. 



The transition from phase to phase requires, as intimated, no 

 great length of time. Tibnadoche polycephala completed the transi- 

 tion from vegetative to fruiting phase in less than twelve hours. 



The germination of the spores ensues closely upon their dispersal 

 or maturity and is unique in many respects.- The wall of the spore 



1 Harper in Botanical Gazette, Vol. XXX., p. 219. 



- The following germination periods are furnished by Dr. Constantineanu 

 {Inaugural Dissertation ueber die Ent<wickelungsbedingungen der Myxomy- 

 ceten; Halle, 1907). 



Reticularia ly coper don 30 to 60 min. 



Fuligo ovata 30 to 90 min. 



Stcmonitis splendens 5 to 6 hrs. 



Perichaena depressa 5 to 8 hrs. 



Amaurochaete atra 6 to 10 hrs. 



Arcyria incarnata 8 to 10 hrs. 



Lycogala epidendrum to 60 hrs. 



Physarum didermoides 1 to 10 da. 



Dictydium cancellatum 1 to 20 da. 



These records are for sowings in drop cultures, in distilled water, kept at 

 temperature of 65°-70° F. (18°-20° C). 



Our own experiments have been made both with distilled water and tap- 

 water with the advantage in favor of the latter. Dictydium cancellatum 



