270 PROF. ALLMAN ON THE BECENT BE8EARCHES 



At the anterior end of the animal, just below the root of 

 the flagellum, and at the boundary between endosarc and ec- 

 tosarc, there is imbedded in the endosarc a roundish, smooth, 

 rather strongly refringent body, whose significance has not 

 been determined. It projects beyond the boundary of the 

 endosarc, and appears to be surrounded by a clear area, which 

 separates it by a considerable space from the ectosarc, nnd by a 

 much narrower space from the endosarc in which it is imbedded. 

 This area is extended forward in a point reaching the surface 

 of the body close to the root of the flagellum ; but whether 

 it communicates here with the exterior could not be determined. 

 The body thus enclosed within the clear area shows in its interior 

 a great number of sharply defined, spherical, clear corpuscles ; and 

 it can slowly but distinctly change its shape, appearing at one 

 time oval, then quite spherical, then more irregular with rounded 

 angles— characters which the author considers incompatible with 

 the supposition of its being either a nucleus or a nucleolus, in 

 the latter case with the surrounding clear area representing the 

 body of the nucleus. 



The liability, however, of the nucleus or nucleolus to changes of 

 form ought not to surprise us. Hanstein has shown the occur- 

 rence of amoeboid changes of form in the nucleus of a great num- 

 ber of plant-cells* ; Alexander Brandt has demonstrated similar 

 changes in the nucleolus of the egg in BlaUa\; and Eimer has 

 shown that the germinal spot (nucleolus) in the egg of the Silu- 

 rus glanis and that of the Carp exhibits amoeboid changes like 

 those of the colourless blood-corpuscles $. 



Under the name of Plahopus ruber (fig. 4), F. E. Schulze § de- 

 scribes an amoeboid rhizopod, which is rendered very remarkable by 

 the peculiar condition of its pseudopodia. These are in the form 

 of thin membranes, which may extend themselves over the surface 

 of other bodies or project free into the surrounding water. They 

 form either a single very thin plate which spreads over the sup- 

 porting body, or they consist of several lamellae which unite with 



* Botanische Zeitung, 1872. 



t "Feber active Formveranderungen des Kernk(3rperchens," Arch, fur mikr. 

 Anat. vol. x. p. 505. 



t " TJeber atnoboide Bewegungen des Kemkorperchens," Arch, fur mikr. Anat. 

 vol. xi. 1875. 



§ Arch. f. mikr. Anat. vol. xi. 1875. 



