THE PROTEUS ANIMALCULE {Amceba proteus) 



Amceb^ are found amongst debris deposits or on mud in fresh-water pools 

 and slow-flowing streams. They are mostly invisible to the naked eye, rarely 

 exceeding one quarter of a millimetre in diameter. 



Place a drop of water containing Amoebae on a slide, cover it with a cover- 

 slip, and examine with the low power of the microscope. 



Form and General Structure. 



Note that the general form of Amceba is irregular and continually changing, 

 the protoplasm flowing out into blunt processes called lobopods or pseudopodia, 

 by means of which it moves and secures its food. 



Ectoplasm 



Endoplasm 



8 



CP 



- Pseudopodia 



^, Nucleus 

 , Sand grains 







Contractile vacuole 



vSfcwO 



Food vacuoles 



Fio. 1. — Amceba proteus {highly magnified). After Grnber. 



Examine the specimen under the high power and note the structure. The 

 body is a naked mass of protoplasm, not uniform throughout, but showing two 

 distinct portions : 



(a) The ectoplasm or ectosarc, a thin film, forming the clear outer portion 

 of the body. 



{b) The endoplasm or endosarc, forming the inner portion. It is granular, 

 and the granules render the flowing movements of the protoplasm 

 visible. Within it are seen the following structures : — 



(i) The nucleus, a spherical body, denser than the rest of the 

 endoplasm. 



