MICROSCOPIC ORGANISMS IN INTESTINAL CANAL. 265 
After continuing to progress through the medium for variable 
periods, the Amcebee either cease to move, and remaining more or 
less isolated, become encysted, or becoming aggregated into 
masses give origin to sporangia. Where they are present in 
abundance, and where the conditions of the medium are unfa- 
vorable to sporangic development, the accumulation of en- 
cysted bodies on the surface often covers the medium with a fine 
greyish bloom, which, unless closely examined, may readily be 
ascribed to the presence of mycelial elements. ‘The encysted 
bodies are either quite free or are associated in little groups and 
knots. As arule, no further change appears to occur within 
them, and they remain unchanged for indefinite periods, ready 
to resume activity when favorable conditions again present them- 
selves. In place of becoming encysted, however, we normally 
find thea Amcebee, after some time, becoming more sluggish in 
their movements, and adhering to one another in pairs or groups 
of various sizes, the union becoming very intimate, and in some 
cases proceeding to such a degree of apparent fusion that we are 
only able to estimate the number of individual elements entering 
into the formation of a group by the number of nuclei or of 
rigidly dilated contractile vesicles which may persist (Fig. 15). 
This phenomenon is so far parallel to that occurring in the case 
of various Rhizopodous organisms, such as Actinophrys sol, &c., 
Fic. 13.—Compound body formed of three conjugate Ameebe: x 1000. 
but the results following adhesion and union rather resemble 
those following the formation of Plasmodia in Myxomycetes, as 
the formation of the compound body is distinctly the antecedent 
to spore formation, the protoplasmic material becoming in greater 
part resolved into a mass of spores or reproductive cells, while a 
certain amount of it remains as an investing and intercellular 
/ VOL, XXI, —NEW SER, s 
