OF THE AM(EBJiA OR A]H(EBINA. 



549 



family. The following species, however, are distinguished, although it is hard 

 to define specific form in such variable creatures, 

 Amceba Pnnceps (xxi. 4). — Colom- 



pale yellow, processes numerous, of a 

 cylindrical outline, with thick, rounded 

 extremities. Its figure when in a passive 

 or non-reptant condition is globidar ; but 

 this character is of no specific value, the 

 natural tendency of any similar semi- 

 fluid, mucous particle being, by the 

 force of cohesion, to assume such a form. 

 Amongst NavmdcB and Algae in fresh 

 water. 1-140" to 1-70", 



A. rerrucom. — Smaller than the last ; 

 colomless ; processes globular, ovoid, of 

 a wart-like appearance. Motion sluggish, 

 like, indeed, all Amcehce. Never exceeds 

 1-240". Amongst aquatic plants. 



A. diffluens. — Colomless j expands into 

 a filmy form and throws out processes 

 which are longer than those of A. verru- 

 cosa, and rather pointed at the ends. 

 This species is a very interesting object 

 under the microscope : at times it re- 

 sembles a tm'bid lump of jelly-looking 

 matter, at others a transparent gelati- 

 nous film, with numerous outstretched 

 processes slowly protruded at one part 

 and withdrawn into the general mass at 

 another, but so acted on as to serve to 

 produce a very slow onward movement. 

 Its movements may be compared in ap- 

 peai-ance to those which may be imagined 

 as exhibited by a many-footed animal 

 tied up in a sack. Usual size 1-300". 

 Common amongst Lenmae. 



A. radiosa (xxii. 1-3). — Colourless; 

 smaller than A. diffluens ; processes nu- 

 merous, long, slender, pointed, disposed in 

 a radiating manner. When contracted, it 

 resembles A. diffluens in its globose figure. 

 Colouring matter is readily taken into 

 its substance. In bog-water. 1-240". 



A. longipes. — Very small ; processes 

 very long, one of them often fom- times 

 the length of the body ; acute and hya- 

 line, without expansions. 1-2500". Ciix- 

 haven, in the sea. 



A. Roeselii (Duj.). — Diaphanous; pro- 

 cesses numerous, some very obtuse, others 

 digitate, and others also pointed or 

 jagged. 1-1.30". Large vacuoles occur 

 about the middle of the body, looking 

 like large globules. 



A. marina (D.). — Filled with granules 

 at the centre ; differs fi-om A. diffluens 

 only in its dimensions and habitat, i. e. 

 the sea. 1-260". 



A. Gleichenii (D.). — ^\''aries from a glo- 

 bular to a veiy long-oval figm-e ; dividing 

 into two or three lobes on one side; 



vacuoles, and some nearly opaque gra- 

 nular bodies, at the centre. 1-400'^ to 

 1-300". 



A. multiloba (D.). — This may be but a 

 [ variety of A. Gleichenii, but deserves 

 pointing out, as much from the circum-' 

 stance of its habitat as from its form. 

 1-1300". It seems softer than other 

 species, and moves actively, emitting 

 from its border in various directions ten 

 or twelve rounded lobes, which give it a 

 most irregidar figure. It was foimd in 

 an infusion of meal which had been kept 

 nearly two months. 



A. Limax (D.) (xxn. 4-6). — Diapha- 

 nous, roimded on each side, more or less 

 globose, and but slightly lobed; glides 

 along in a nearly straight line ; contains 

 very distinct granides, and a very clearly 

 marked vacuole. Found in Seine water 

 kept for eight months. It may be but a 

 more advanced degree of development 

 of the preceding, or of the following 

 species; its greater transparency, how- 

 ever, and its semi-fluid consistence, seem 

 sufliciently distinctive. 1-260" to 1-800". 

 Auerbach suggests that this species is 

 only a young form of A. Princeps. 



A. Guttula (xxii. 6). — Diaphanous, 

 orbicular or ovoid ; glides in a straight 

 course, and contains very distinct gra- 

 nules. This is one of the most common 

 species, but may easily escape notice on 

 account of its great transparency, the 

 simplicity of its form, and the slowness 

 of its movements. In river- or marsh- 

 water, kept for some time_, containing 

 plants. 1-520" to 1-890". 



A. lacerata (D.). — Symmeti-ical, ru- 

 gose, plaited, and gTanular, rather dia- 

 phanous, with broad expansions, looking 

 membranous at the base, temiinated by 

 several tapering torn points ; one or more 

 evident vacuoles. 1-2800" to 1-890". In 

 pond-water. 



A. hrachiata (D.). — Globidar; semi- 

 transparent, porous and tubercidar, with 

 four to six very thin long and cylin- 

 drical expansions, straight or flexuose, 

 sometimes bifid or branching. In animal 

 infusions. 1-190". 



A. crassa (D.). — More or less rounded, 

 thick ; contains nimierous granides ; ex- 

 pansions rounded, numerous, not very 

 prominent. 1-880" to 1-520". In the 

 water of the Mediten-anean. 



A. rajnosa (D.). — Globular or ovoid; 

 granides veiy numerous ; expansions nu- 

 merous, of nearly equal size, roimded at 



