34 
Amoeba Chironomi, Nov. Sp. 
nucleus appears as a clear, refractile, vesicular mass. The general 
protoplasm is divisible into a clearer ectoplasm and a granular endoplasm 
(Figs. 2, 3, etc.). Pseudopodia are formed during movements of locomo¬ 
tion by an outflow of the ectoplasm at right angles to the long axis of 
the body of the Amoeba (Figs. 3, 10, 11, 12). Into this ectoplasmic 
process the granular endoplasm streams and soon becomes concentrated 
there (Fig. 16). The pseudopodium then swells out and the Amoeba 
Figs. 1—15. Drawings, showing variations in shape and reversal of direction of motion 
of an Amoeba chironomi, made from a single living specimen during a period of 45 
minutes, at intervals of approximately 3 minutes. 
Fig. 1. A. chironomi with somewhat broad, blunt pseudopodium partially withdrawn. 
Contractile vacuole ( c.v.) expanded. Nucleus (n) present. 
Fig. 2. Long pseudopodium forming before previous one is entirely withdrawn. The 
spindle shape of the organism is the result of change of direction of motion. 
Fig. 3. Oval shape, with single pseudopodium, where the clear ectoplasm is well seen 
in contrast with the granular endoplasm. 
Fig. 4. Disappearance of pseudopodium. 
Fig. 5. Contractile vacuole (c.v.) piartly contracted. 
Fig. 6. Contractile vacuole widely expanded again. 
Fig. 7. Shape of organism now almost oval. 
Fig. 8. Contractile vacuole reduced in size again. 
