THE MYXOMYCETES OF PICTOU COUNTY. MOORE. 169 



of a hyaline protoplasmic ground substance which, in the 

 periphery, is free from granules, but within is filled with 

 plasmodic grains and frequently grains of carbonate of lime, 

 and shews also numerous vacuoles. The interior is also tra- 

 versed by a network of channels in which streaming movements 

 are continually going on. The flow in these channels is rythinic, 

 persisting in one direction for a period of from one to two 

 minutes, then reversing and continuing in the opposite direction 

 for a similar period. The streaming, 'however, continues for a 

 somewhat longer period in tttie direction of the general move- 

 ment of the plasmodium. This advances by the ectosare push- 

 ing out in the direction of movement followed by a flow of the 

 interior granular substance. Then follows a short pause, dur- 

 ing Avihich tihe advancing margin withdraws somewhat, but some 

 of the gain made is retained. The next onward movement of 

 the ectosare carries the border beyond the line previously 

 attained. In this way, by a series of pulsations, a general 

 onward movement of the mass is accomplished. 



Numerous nuclei are observable in the substance of the plas- 

 niodium, and, as its mass increases, tjiere is a corresponding 

 increase in the number of nuclei by karyokinetic division. The 

 nuclei are undoubtedly those of the original swarmers which 

 coalesced to form the plasmodiuni, and the product of their 

 division. 



In addition to the nuclei, plasmodic granules and refuse or 

 semi-digested material, there are found in the interior of the 

 plasmodia of many species, granules of tiie carbonate of lime. 

 Associated with the granules, more particularly those of lime, 

 are the pigments which imp-art to many plasmodia bright and 

 characteristic colors. The plasmodia of Pliysarum virescens 

 and Fiiligo ovata, for example, exhibit brigjht shades of yellow, 

 that of Pliysarum globuliferum has a delicate lavender coloring, 

 that of Lycogala epidendrum a faint rose. The prevailing color 

 among plasmodia, however, is a watery or opaque white or grey. 



