206 PUOT". ALLMAN ON TUL: BECENT RESEARCHES . 



very nearly to the Bhizopoda with the limits assigued to this group 

 by Max Schultze. Hertwig and Lesser, however, substitute" for 

 the designation Ehizopoda in the Schultzian sense that of Sar- 

 codina, and confine the former to ouc of the sections into which 

 they have divided their group of the Monothalamia. 



From these general remarks we may now pass to the more im- 

 portant special forms to which the attention of zoologists has been 

 recently directed. 



Dactylonpheprmm vitrcmn. a, pseuclopodium in the act of withdrawal ; h, food- 

 pellets; cc, non-coutractile vacuoles. (After Hertwig and Lesser.) 



Under the name oiDacU/losphcerium vitreiim (fig. 1), Hertwig and 

 Lesser describe a freshv.ater rhizopod which but slightly differs 

 from Amoeba. It has a roundish body composed of homogeneous 

 hj'^aline protoplasm with a multitude of yellow or green strongly 

 refringent granules, which fill the whole of the interior of the body 

 as far as a narrow hyaline margin. The pseudopodia are blunt 

 finger-shaped processes which radiate in all directions from the sur- 

 face, and consist of a perfectly homogeneous hyaline protoplasm. 



The mode in which the pseudopodia are withdrawn is peculiar. 

 "When one of these is about to disappear, it seems suddenly to 

 change its form ; its smooth surface becomes nodular and irregu- 

 larly sinuous, it conveys the impression of having suddenly lost 

 its turgescence, and then it rapidly flows back into the body. 



Numerous non-contractile vacuoles exist ; but the multitude 

 of coloured corpuscles so interfered with the transparency of the 

 protoplasm, that it was impossible to decide with certainty as to 

 the presence of a nucleus. 



In a variety in which the yellow corpuscles are replaced by 



