344 W. ARCHER. 



foreign bodies, such as bacteria, frequently attached to the 

 superficies of the sarcodine, as they are passively carried 

 onwards. This rotation is not confined to the outer layer, 

 the whole body-mass partakes of it : by focussing-in, they 

 could see that each granule described its circuit, the nucleus, 

 though nearly central, making its comparatively short excur- 

 sions, sharing, as it must, in the rotating movement of the 

 whole body-mass. 



This interesting kind of protoplasmic movement, the 

 authors think, can be explained only by assuming that every 

 point of the body possesses a nearly equal amount of con- 

 tractility, as Max Schultze did to explain the protoplasmic 

 current. Were there a passively moved endosarc and an 

 actively moving ectosarc, the former could be only mechani- 

 cally set in motion by the latter, its energy getting gradually 

 lost inwards and absolutely ceasing at the middle. But 

 here this is not the case, as there is no difference perceptible 

 in the rate of movement of the inner and outer portions. 



Rolling thus onwards this sarcodine but little alters its 

 general figure, and that only from more or less of an oval to 

 round, its upper elevation the Avhile more or less steep or 

 depressed. An alteration of the direction of movement is 

 brought about by an alteration of the direction in which the 

 body-parts rotate. 



The authors did not directly observe the inception of food, 

 which must become simply pressed inwards as the organism 

 glides onwards. 



Its size is very variable, its longitudinal diameter being 

 from 0-03— 0-06 millimetres. 



Dactylosphcerium vitreum, Hertwig et Lesser,^ (figs. IV, 18) 



Under the foregoing common name, the authors, ad 

 interim, combine two forms, agreeing indeed in their main 

 characters, but still showing some constant differences, and 

 therefore probably, in reality, distinct species. Both possess 

 an irregularly rounded figure, from about '06 to 'OlS milli- 

 metres in diameter. The protoplasm is hyaline, containing 

 immersed therein a great number of variously sized, 

 coloured, strongly refractive granules. In one of the forms 

 these are constantly of a bright clear yellow, in the other 

 constantly green, these differences accompanied by other 

 minor ones proper to each. These coloured elements are 

 crowded and fill the body-mass all but a narrow hyaline 

 border ; so crowded are these that the authors were unable to 



' Loc. cit., p. 54, t. ii, fig. 1, A and B. 



