48 BRITISH FRESHWATER RHIZOPODA. 



to raise a doubt whether it really belongs to this 

 species. Leidy, however, figures it as a form of A. 

 proteus ( ( Freshw. Rhiz. N. Amer.', pi. i, fig. 4), and it 

 may for the present be distinguished as var. granulosa. 

 It has been held that inasmuch as A. proteus repro- 

 duces by fission, the protoplasmic body may be divided, 

 and propagation effected by artificial severance. This 

 we think is more than doubtful. Gruber's investiga- 

 tion of the nucleus and its relation to the plasm, years 

 ago, seemed to dispose of it. Deprived of the nucleus, 

 says this observer, the plasma cannot sustain life. 

 " The nucleus needs the plasm; the plasm the nucleus." 

 Occasionally, though very rarely, an injured Amqeba is 

 -met with, and the injury may result in the death of the 

 individual. A case of this kind, which came within our 

 own observation, has already been described (see pp. 

 28-29, f. 15). 



2. Amoeba actinophora Auerbach. 

 (Plate I, figs. 7-10.) 



Amoeba actinophora AUERBACH in Zeits. f . wiss. Zool. YII 

 (1856), p. 392, t. xx ; MAGGI in Rend. R. 1st. Lomb. (2) 

 X (1877), p. 316 ; GRUBER in Zeits. f. wiss. Zool. XXXVI 

 (1881), p. 464, t. xxx, ff. 9-17, and (Engl. transl.) in Ann. 

 Nat. Hist. (5) IX (1882), p. 110, t. ix, ff. 9-17 ; BUTSCHLI 

 Mikr. Schaume (1892), p. 73, t. ii, ff. 8, 9, and (Engl. 

 transl.) Micros. Foams (1894), p. 107, t. iv, ff. 3, 4; 

 FRENZEL Mikr. Fauna Argent. I, Prot. 3 (1893), p. 89, 

 t. viii, ff. 19, 20, and 4 (1897), p. 147, in Bibl. Zool. IV; 

 CALKINS Prot. (1901), p. 38. 



? Cochliopodium actinophorum PENARD Faune Rliiz. Leman 

 (1902), p. 188, ff. 



Plasma-body minute ; when active resembling the 

 smaller forms of Gochliopodium bilimbosum, with a 

 rounded outline, from one side of which two to six 

 (sometimes more) short, simple, or branching pseudo- 

 podia are protruded. According to Auerbach the 

 protoplasm is " distinctly surrounded by a double 

 contour," and the animal appears as if " covered by 



