474 SUMMAKY OF CURRENT RESEARCHES RELATING TO 



part of the fluid showed hundreds in the field. They varied greatly 

 in size, and had a remarkably active amceboid movement. Generally 

 a nucleus in vacuo could be distinctly seen. They seem not to make 

 their appearance in watsr and egg alone, and apparently flourish best 

 when ammonium tartrate is re^jlaced by pepsin. 



New Rhizopoda.* — M. A. Korotneff describes some new forms, 

 the first of which he calls Protamceba primordialis (n. gen. et sp.) ; 

 the name Protamceba has, however, been already used (see, e. g. 

 Macalister, Introd. Anim. Morph., p. 49, fig. 1) ; this new form is one 

 of the Monera. 



The next new genus is Dactylamceba elongata (PL VI. Fig. 1 x 540) ; 

 its elongated body is divided into an anterior portion which is perfectly 

 transparent, and a posterior which is granulated ; in front we find 

 long conical pseudopodia directed forwards. In the binder part 

 there is a central granular mass, containing brown elements, while 

 the peripheral envelope is hyaline and gives ofi" short, obtuse, or even 

 lobate pseudopodia. Quite at the extremity there are small delicate 

 prolongations which appear to serve as points of support for the 

 animal. There are two vacuoles which pulsate alternately. The 

 whole creature is only 0'13 mm. in length. 



Longicauda amcebina (n. gen. et sp.) (Fig. 8 X 540) is a form with 

 a reniform nucleus, which has a well-marked contour, though no 

 envelope could be demonstrated ; there is a tail made up of three 

 comjdetely independent parts, which ramify like a deer's horns ; the 

 branches retain their form, owing to the presence of a firm envelope, 

 so that they are permanent pseudopodia. 



In the genus Pelomyxa, the author describes a new species, 

 P. parvialveolaia, and gives some notes on the history of P. palustris 

 Greef; he finds himself in general agreement with the German 

 observer. Within the substance of the Amoeba in question are found 

 (Fig. 2 X 1100) shining bodies, altogether hyaline in character, 

 rounded in form, and varying in size (from • 005 mm. to * 008). 

 These bodies elongate, become biscuit-shaped, and divide into 

 two spheres. When they are beginning to undergo a change they 

 enlarge at one point (Fig. 3) and become filled with the protoplasm 

 from the body ; thus growing they become spherical (Fig. 4), leaving 

 a small orifice for the entrance of the protoplasm ; meantime the 

 walls swell, and soon the orifice becomes closed up (Fig. 5). In one 

 specimen of Pelomyxa the author found a number of spherical capsules 

 completely closed, and with delicate, highly refractive walls. Within 

 this capsule there was a finely granular plasma, and a small rounded 

 body which appeared to be a " shining body " (Figs. 6 and 7) ; these 

 capsules were distinguished by the presence of a vacuole, but the 

 author was unable to follow their history any further. He is, how- 

 ever, of opinion that, as Greef thinks, the shining bodies are the spores 

 which give rise to young Amoebce. 



The author concludes with some remarks on Cochliopodium and 

 on the development of Acantliocystis viridis, where he finds that the 

 small ovoid bodies described by E. Hertwig are true embryos- 

 * Aich. Exp. et Gen. Zool., viii. (1880) pp. 467-83 (2 pis.). 



