202 DEscEiPTioN OF \^Pohirjastrica. 



form, with the tenninations thick and rounded. This curious crea- 

 ture, from its slow motion and yellowish colour, is a desirable object 

 for the microscope ; its singular changes of form, and its internal 

 organization, may be viewed with considerable pleasure, under very 

 high magnifying powers. Its normal shape, if such it can be said 

 to possess, is globular, but it can relax any portion of its body, and 

 contract the rest, so as to force the internal part down into this 

 relaxed portion, which thus becomes so to speak, a hernial tumour ; 

 ten or twelve processes may sometimes be seen extended at one time. 

 Figures 85, 86, and 87, represent three animalcules highly magnified ; 

 the first has only two processes extended; in the last there are 

 several. Foimd amongst Naviculco. Size 1- 140th to 1 -70th. 



Amceba verrucosa. — Body less than that of the last species, and 

 coloTirless ; globular or ovoid processes, very short and blunted, re- 

 sembling warts; motion sluggish. Size never exceeding 1 -240th. 



A. diffiuens ( Vohox sphoerula, M.) Body expansible and colourless; 

 processes longer than the last, strong and more pointed. This species 

 is a very interesting object for the microscopic observer ; its body 

 resembles sometimes a transparent, at others a turbid lump of 

 jelly, slowly expanding and stretching itself out, and here and there 

 exhibiting its pointed processes, which again disappear as it advances. 

 Its motions may be compared to those of a many-footed animal tied 

 up in a sack. Found in Hackney Marsh, amongst Lemna. Usual 

 size about 1 -300th. 



A. radiosa. — Body colourless, and less than that of the preceding 

 species ; its processes, which are numerous, are long and slender, 

 pointed at the ends, and apparently radiating. This animalcule, 

 when in a contracted state, is not distinguishable from the A. diffluens, 

 but when fully expanded may be likened to a porcupine. It 

 readily imbibes colouring matter. Fig. 88 resembles one of these 

 creatures in a contracted state, and 88* the same with the processes 

 thrust forth. Found in bog- water. Size 1 -240th. 



A. longipes. — Very small ; processes very long ; a single one, often 

 four times longer than the body, acute, hyaline. Body 1 -2500th. 

 In North Sea, at Cuxhaven. 



A. Roeselii (Duj.) — Diaphanous, expansions numeroiis, some very 



