AMOEBA PBOTEr>. 45 



DEE in Acta Soc. Fauna Fenn. XII (1894), no. 2, p. 8; 

 RHUMBLER in Arch. f. Entwick. VII (1898), p. 169, f. 29: 

 STENROOS in Acta Soc. Fauna Fenn. XYII (1898), no. 1, 

 pp. 32, 85 ; SCHEEL in Sitz.-ber. Ges. Miinchen, XV (1899), 

 p. 90; in Festsch. C. von Kupffer (1899), p. 569, t. li ; 

 and (abstr.) in Amer. Nat. XXXIV (1900), pp. 332, 441 ; 

 ZACHARIAS in Biol. Centralbl. IX (1899), p. 58 ; CALKINS 

 Protozoa (1901), passim, ff. 10A, I?A, 49, and in Amer. 

 Nat. XXXV (1901), p. 645, etc.; ISSEL in Atti Soc. 

 Torino, XXXVI (1901), p. 68, and in Atti Soc. Ligust. 

 XII (1901), p. 146 ; MASTERMAN Zool. (1901), p. 85, f. 27 ; 

 G. S. WEST in Journ. Linn. Soc., Zool. XXVIII (1901), 

 p. 309, and op. cit. XXIX (1903), p. 109 ; STOLC in Zeits. 

 Allg. Physiol. I (1902), p. 209. 



Amoeba commnnis DUNCAN in Pop. Sci. Rev. XVI (1877), 

 p. 233, tt. v, vi. 



Amoeba c/mosLEiDY in Proc. Acad. Nat. Sci. Phil. 1878, p. 99. 



In general aspect, as well as in size, extremely 

 variable ; endoplasm colourless or greyish granular, 

 frequently containing desmids and other chlorophyllous 

 algae, or their remains, which have been incepted as 

 food, also numerous refringent globules of variable 

 size, and minute crystals of (apparently) calcium car- 

 bonate. Body when at rest irregularly spherical, or 

 ovoid; but in motion exhibiting a tendency to differen- 

 tiate into anterior and posterior extremities lobate 

 expansions being protruded anteriorly or to form 

 digitate pseudopodia, which sometimes develop short 

 lateral branches ; the posterior extremity often ter- 

 minating in a protuberance, expansion, or mulberry- 

 like bulb. Pseudopodal movements frequently very 

 active ; at times sluggish. The contractile vesicle 

 (usually single) situated behind the nucleus, which is 

 ovoid, with a punctated surface, and usually large and 

 conspicuous. 



Dimensions : Frequently 200 p, in diameter in the 

 globular form, 300 x 150 /x when ovoid ; radiate or 

 dendroid, palmate, and cylindroid forms varying from 

 0*5 mm. to 1 mm. according to Leidy. Elongate 

 variety (PI. Ill, fig. 2), 400-450 /u. 



