166 THE MYXOMYCETES OF PICTOU COUNTY. MOORE. 



and, before long, each becomes somewhat elongated or pear- 

 sihaped and develops a flagellum, by means of which, it is able 

 to move rapidly through the water with a characteristic jerking 

 motion. During this stage the " swarmers," eo called, increase 

 rapidly in number by division ; but eventually they settle down, 

 the flagella are withdrawn and they again assume the amoeboid 

 form, creeping over the substratum. Soon a number of the 

 amoebae coalesce to form a small protoplasmic mass which con- 

 tinues to exhibit amoeboid movements as a whole and character- 

 istic internal protoplasmic streamings. The plasmodium, as the 

 protoplasmic mass is now called, increases in size by fusion with 

 other amoebae and by the ingestioni -and assimilation of food 

 material until the condition of maturity is attained whicth leads 

 to the fruiting or reproductive phase. The whole plasmodium now 

 becomes heaped up into a number of protuberances into which 

 the whole of its protoplasm passes, with the exception, in some 

 cases, of a small portion which remains behind to form a film- 

 like coating over the substratum and which is known as tlie 

 hypothallus. When these protuberances are distinct from each 

 other they are known as sporangia, and these may be either 

 sessile or stipitate. The stipe may be prolonged into or through 

 the cavity of the sporangium to form a columella. When the 

 sporangia are vein like or sinuous, retaining largely the charac- 

 teristic form of the plasmodium, the fructification is described 

 a-5 plasmodiocarpous, or as a plasmodiocarp. In other cases the 

 sporangia are partially fused together, the walls between them 

 may be imperfectly developed and their individuality to a cer- 

 tain extent lost. Sucih a form of fructification is known as 

 an sethalium and is well exemplified by such a species as Fulifjo 

 ovata. 



The protoplasm of the interior of the Sporangia is for the 

 most part converted into spores ; but a residual portion fre- 

 quently gives rise to a capillitium. This may consist of a net- 

 work of threads or tubules extending throughout tdie cavity of 



