374 KLEMENTARY BIOLOGY. [ClIAP. 



1. Size; differing considerably in different specimens. 

 Measure. 



2. Outline; irregular, produced into a number of tliick 

 rounded eminences {pseudopodia) which are con- 

 stantly undergoing changes: sketch it at intervals of 

 five seconds. 



3. Struct u?-e. 



a. Outer hyaline layer (eetosare), tolerably sharply 

 marked off: inner granular layer (e/idosare) be- 

 coming more lluid centrally. 



I'. Nucleus (indistinguishable in some specimens); 

 a roundish more solid-looking body, often highly 

 granular. There may be one, two, or many. 



€. Contractile vesicle; (if present) a roundish clear 

 space in the eetosare which disappears peri- 

 odically, and after a short time reappears; its slow 

 diastole — rapid systole, 



d. Ingested foreign bodies; Diatom cases, Des- 

 midicc, (Sec. 



4. Movements. 



a. AVatch the process of formation of a pseudopo- 

 dium. A hyaline ectosarcal lobe first appears; 

 then, as it increases in size, the granular endosarc 

 flows into it. 



h. Locomotion ; watch the process, — a pseudopodium 

 is thrown out, then the rest of the body is drawn 

 up to it, and the process is repeated. 



c. If the opportunity presents itself, watch the pro- 

 cesses of the ingestion and egestion of solid 

 matters. 



