ASTASLEA. 



ASTERIGERINA. 



liform filament single, arising- suddenly from 

 the anterior part of the body, or from a 

 more or less deep notch in it ; oral aperture 

 very extensile (Kent), leading to a long 

 oesophagus. 



Dujardin forms an unnecessary genus, 

 Per cinema, to contain those species in 

 which the filament arises from the gradu- 

 ally narrowed anterior extremity of the 



A. hamatodes, E. (PL 30. fig. 16). Fu- 

 siform, tail very short j at first green, then 

 red ; length 1-380". 



The flagelliform filament was absent in the 

 specimens represented in the figure. The 

 substance of the body was insoluble in cau- 

 stic potash, even when heated to boiling, 

 merely becoming swollen. It exhibited nu- 

 merous vacuoles, which in some of the or- 

 ganisms were filled with green grains of 

 chlorophyll. The colour arose from di- 

 stinct granules of pigment, scattered through 

 the colourless substance ; when treated with 

 solution of iodine and then sulphuric acid, 

 the Astasice became spherical, and were co- 

 loured blue, bluish green, and purplish blue, 

 the purple tint apparently indicating the 

 presence of cellulose. It was, however, 

 afterwards found that these colours were 

 produced by the acid alone. 



This curious organism colours the water 

 of ponds &c. blood-red. 



A. limpida, D. (PL 30. fig. 17). Fusi- 

 form, colourless ; length 1-550". 



There are other species ; but they are ill- 

 defined. A. nivalis, Shuttle-worth, found in 

 red snow, would appear to be an active form 

 of Protococcus nivalis. 



BIBL. See ASTABIJEA; also Shuttleworth, 

 Bibl de Geneve, Feb. 1840; Kent, In/us. 

 p. 375. 



ASTASWE'A, Ehr. A family of Flagel- 

 late Infusoria. 



Char. Body of spontaneously variable 

 form, mostly with one or more flagelliform 

 filaments, "insoluble in solution of caustic 



This family corresponds nearly to the Eu- 

 glenia of Dujardin, who asserts the existence 

 of a contractile integument. Form of the 

 body variable, sometimes becoming sphe- 

 rical, at others cylindrical, fusiform, &c., 

 and exhibiting a head or tail-like process, 

 or both. The Astasiaea are distinguished 

 from the Amcebsea by the absence of the 

 irregular processes sent out by the latter 

 from all parts of the body ; and by the pre- 

 sence of a distinct mouth. 



The forms included under the family thus 

 characterized are still very imperfectly un- 

 derstood ; and it is probable that some of 

 them, separated generically by Ehrenberg, 

 are only transitional conditions of others. 

 Infusoria exactly resembling Astasia hcema- 

 todes and Euglena viridis occur without the 

 flagelliform filament; Euglena also occurs in 

 a resting form, surrounded by a gelatinous 

 envelope, like Chlamidomonasfindi undergoes 

 division into 4, 8, 16 or more new indivi- 

 duals in this state, so as to form irregular, 

 floating Algoid patches. The green bodies 

 make their escape from the gelatinous enve- 

 lopes under certain circumstances, just in 

 the same way as the zoospores escape from 

 the cells of the Oonfervoid Algae. This 

 resting form also exhibits another character, 

 especially in winter; the gelatinous envelope 

 acquires a firm, dense, membranous coat over 

 its periphery, like the resting spores of the 

 Confervoids, and in some cases this coat is 

 polygonal and marked with ridges &c. It 

 is probable that the colour of the species is 

 not constant, since it seems to depend upon 

 similar substances to that of the Palmellaceae, 

 which are known positively to change from 

 green to red, and vice versa, and even to fade 

 into an almost colourless state when kept in 

 the dark. These organisms still require much 

 careful examination, not of isolated speci- 

 mens, but by watching their developmental 

 history constantly for extended periods and 

 through different seasons. More is said on 

 this subject under PROTOCOCCUS. 



The following Table gives the genera of 

 Ehrenberg and Dujardin : 



Attached .................................... Colacium, Ehr. 



Unattached. 



Two eye-spots .................. ......... Distigma, Ehr. 



One flagelliform filament. 

 bneeyerspot. 



With a tail-lite process ...... Euglena, Ehr. 



Without ...... Amblyophis, Ehr. 



Two flagelliform filaments. 

 Both alike. 

 Animals green, with a red 



eye-spot ........................ Chlorogonium, E. 



Colourless, no eye-spot ...... Zygoselmi8,Duj. 



One anterior, the other trailing 

 and retractile ..................... Heteronema,J)nj. 



Several filaments ' 



BIBL. Ehrenberg, Inf. ; Dujardin, Infus.; 

 Morren, RuUfact. d. Eauxj Brux. 1841 ; 

 Cohn, Protococ. pluv., Nova Acta Ac. L. C. 

 N. C. xxii. p. 397. (Abstr. Ray Soc., Bot. 

 1853, p. 352.) 



ASTATHE. See PRIMORDIAL UTRICLE. 



ASTEKEGERI'NA, D'Orb. A pseudo- 

 genus of Foraminifera, comprising species 

 G 2 



