PLATE XIX. 
Vol. XX. Royal Physical Society, Edinburgh. 
Fic. 1.—A. proteus X. Fie, 2.—A. proteus Y at X end of series. 
Fic. 3.—A. proteus Y at Z end of series. 
N, nucleus; , food vacuole ; (.V, contractile vacuole, - 
All the figures are drawn from living material, with the aid of an Abbé camera. 
