DR. SCHULTZE, ON THE RHIZOPODA. 145 



individuals or as colonies, and on the occurrence and the col- 

 lecting of living marine Rhizopoda. 



To this part of the work are added remarks upon the classi- 

 fication of the Rhizoj)oda, including a tabulated view of the 

 families and genera, and the description, with beautiful 

 figures, of the species observed ]jy the author in the living 

 state, of which we subjoin a list : — 



Gramia. liotalia. Textilaria. 



Lagynis. Itosalina. Polystomella. 



Squamidina. Polymorphina. Acervulina. 

 Miliola. 



Dr. Schultze commences his description of the structure 

 and vital phenomena of the Rhizopoda by referring to the 

 well-known protozoon Amcpba, Ehr. (Proteus, O. Muller) ; 

 which may be thus briefly described : — Its body consists of a 

 transparent, colourless, contractile substance, whose individual 

 life is manifested by various changes of form, bearing the 

 character of voluntary movement. This contractile substance 

 has the property of throwing out from any part of it a 

 rounded or pointed, longer or shorter process, in consequence 

 of which this simplest of animal forms presents the utmost 

 diversity of shape. No distinction can be perceived of mem- 

 brane and contents, and no cilia are ever observable. The 

 utmost powers of the microscope disclose merely a homo- 

 geneous, occasionally fine-granular, transparent (protein-) sub- 

 stance, with irregularly scattered molecular granules, with 

 sharp contours and of strongly refractive properties, imbedded 

 in it, together with some larger, clear, pale vesicles. The 

 former are either fat-drops, soluble in ether, or corpuscles, 

 soluble in a solution of caustic potass, but not so in ether or 

 acetic acid ; and the latter often resemble simple vacuities in 

 the substance, having no walls and filled with a homogeneous 

 fluid. The homogeneous matrix, as well as the imbedded 

 granules and "vacuoles" — as the cavities above described 

 have been termed — are in a continual kind of flowing motion. 

 The substance appears to be throughout equally capable of 

 movement and equally sensitive ; and any part of it appears 

 also to be equally capable of assuming the function of a mouth 

 or vent.* 



In the Adriatic Sea, Dr. Schultze met with an Amceha, 

 differing from the known species belonging to fresh and salt 

 water by the extraordinary extensibility and active motion of 

 the contractile substance of the body. He terms this species 



* Vide Description of Actinophrys Sol, bj' Kblliker, in ' Quarterly 

 Journal of Microscopical Science,' Vol. i., p. 25 ; and Siebold's Observa- 

 tions on Unicellular Plants and Animals. (lb., p. IIL) 



VOL, III. L 



