268 PROP. ALLMAIiT OlST THE EECENT RESEARCHES 



every point of fhe surface may, under the microscope, be seen to 

 be in a constant rotation; so that on tbe dorsal side of the animal 

 (that turned away from the supporting surface) each point travels 

 from behind forwards, while on the ventral side it travels from 

 before backwards, thus causing, by friction against the surface of 

 support, a rolling forwards of the entire animal. This rotation of 

 the superficial particles of the sareode body is rendered apparent 

 by watching the movements of minute foreign bodies which happen 

 to be adherent at the surface. 



It is not, however, in the external layer alone, but in the whole 

 body, that motion of rotation exists. The coloured corpuscles 

 and granules of the endosarc may be seen to be constantly moving 

 in a forward direction on the dorsal side, and in the opposite direc- 

 tion on the ventral side, so that every one of them describes a com- 

 plete circle. Even the nucleus participates in the general rota- 

 tion of the particles, though from its nearly central position the 

 circle in which it rotates is a small one. 



This interesting form of protoplasm motion can be explained, 

 as Hertwig and Lesser remark, only by attributing to every point 

 of the body, as well as of the endosarc as of the ectosarc, a nearly 

 uniform contractility, such as Max Schultze assumes in order to 

 explain protoplasm-currents in general. 



Hertwig and Lesser have not witnessed the actual ingestion of 

 nutriment, though abundant nutriment-masses were seen imbedded 

 in the endosarc, where they lay without being surrounded by any 

 distinct vacuole. 



A. remarkable amoeboid organism, which forms in some respects a 

 transition form between the Amosbce and the Flagellata, has, under 

 the name oi Mastig amoeba aspera (fig. 3), been described by Franz 

 Eilhard Schulze*, who discovered it in a pond of the Botanic Grarden 

 at G-ratz. Like other amoeboids it is very changeable in shape ; 

 but its usual form is that of an appressed oval, from whose sides 

 simple, blunt, finger-shaped pseudopodia are given off. One 

 end is more pointed than the opposite, and from the pointed 

 end, which during locomotion is always turned forward, there 

 projects a long, very fine, non-retractile, cylindrical filament of 

 sareode, in all respects resembling a flagellum of the true 

 Flageliata. The regularly disposed lateral pseudopodia, and the 

 position of the flagellum at the end of the long axis, give 

 to the creature a superficial resemblance to a bilateral animal, 

 -■' F. E. Schulze, " Rhizopodenstudien," Arch. f. raikr. Anat. vol. xi. p. 583. 



