A. E. HILTON ON CAPILLITIA OF MYCETOZOA. 7 



which it then changes are but aggregates of plasm rapidly 

 assuming sporangial shape in virtue of excretions, secretions, 

 condensations, precipitations and interior and exterior surface- 

 strains. If this is forgotten, and Mycetozoa are studied in a 

 purely botanical light, misinterpretations are inevitable. 



It follows from this that the capillitia of Mycetozoa have their 

 origin in the character of the processes by which the plasm 

 of an amoeboid plasmodium is converted into the plasm of 

 innumerable spores. This transformation has a double aspect. 

 It is not only a rearrangement of constituent elements ; it is 

 likewise a renewal of vital energy. That, indeed, is its real 

 and primary significance. The breaking down of the plasm 

 into multitudinous particles is at the same time a process of 

 rejuvenation by elimination of waste materials. In creeping 

 among rotting vegetation on which it feeds, a plasmodium 

 absorbs various substances, chiefly in solution, which along 

 "with by-products of metabolism must be removed before the 

 reproductive powers of the plasm can be regained. When these 

 substances have accumulated until a critical stage is reached, 

 the Plasmodium aggregates and becomes stationary, and elimina- 

 tion proceeds apace. The coarser excretions are precipitated as 

 a hypothallus or substratum, or deposited as a stalk or columella ; 

 other exudations at the surface of the plasm harden into enclosing- 

 walls of the sporangium ; and interior secretions usually furnish 

 materials of a cellulose nature which consolidate into a capilli- 

 tium. While a capillitium is forming, the plasm-mass in which 

 it is embedded shrinks in volume by the loss of exuded fluids 

 «,nd solids, and divides and redivides into smaller and still 

 smaller portions, each of which in turn tends to become rounded 

 by surface-tension ; and it is important to notice that develop- 

 ment of the capillitium proceeds along the channels produced 

 by successive cleavages and contractions of the plasm-masses. 

 In the end, after the capillitium has been deposited, the plasm 

 a,rrives at an extreme state of subdivision in which each particle 

 includes a single nucleus ; and by a final act of excretion every 



