SPIRILLINA. 



[ 596 ] 



SPIROGYRA. 



is also the case with the spirally-arranged 

 green contents of SPIROGYRA ; while this 

 article refers exclusively to cellulose struc- 

 tures belonging to the cell-wall. 



See also CELL,VEGETABLE, SECONDARY 

 DEPOSITS, PITTED STRUCTURES and TIS- 

 SUES, VEGETABLE. 



BIBL. General works on Vegetable Ana- 

 tomy. Schleiden, Ann. Nat. Hist. vi. p. 35 

 (from the Flora, 1839), Taylor's Scient. 

 Mem. ii. p. 281 (from Mullens Archiv, 1838), 

 Principles, p. 42; Griffith, Ann. Nat. Hist. 

 x. p. 109; E. Quekett, Trans. Mic. Soc. i. 

 p. 1, Ann. Nat. Hist. xv. p. 495; Mohl, 

 Verm. Schrift. p. 285 (Ann. des Sc. nat. 2 ser. 

 xiv. p. 242), Vegetable Cell, London, 1852, 

 p. 14, Botan. Zeitung, xi. p. 753 (1853), 

 Agardh, De Cell. Vegetab. Lund. 1852; 

 Cruger, Botan. Zeit. xii. pp.57, 833 (1854), 

 xiii. p. 601 (1855); Caspary, Bot. Zeit. xi. 

 p. 801 (1853) ; Trecul, Ann. des Sc. nat. 4 

 ser. ii. p. 273 ; Schacht, Pflanzenzelle, Berlin, 

 1852, Bot. Zeit. viii. p. 697 (1850) ; Unger, 

 Linncea, xv. p. 385 (1841); Meyen, Pflan- 

 zenphysiologie, i. ; Mitscherlich, Ann. Nat. 

 Hist. ser. 2. i. p. 436. 



SPIRILLINA, Ehr. A doubtful genus 

 of marine Infusoria, of the family Arcellina. 



Char. Shell siliceous, porous, forming a 

 flat spiral. 



S. vivipara. Shell microscopic, hyaline, 

 smooth, containing numerous embryo shells. 

 Found in America. 



BIBL. Ehrenberg, Abhandl. d. Berl.Akad. 

 1841.402,422. 



SPIRILLUM, Ehr. A genus ofVibrionia. 



Char. Consisting of a colourless, tortuous, 

 contractile, but not extensile filament or cy- 

 lindrical spiral. 



These organisms, found in infusions and 

 decomposing liquids, are very interesting 

 objects on account of the remarkable cha- 

 racter of their corkscrew-like movements. 

 They multiply by transverse division, sepa- 

 rating into two portions while in motion. 

 They are jointed (or septate ?), but the joints 

 are not always easy of detection. They are 

 insoluble in boiling potash. Their structure 

 is best examined when they are preserved in 

 a dry state. It is difficult to know where to 

 place them in a system, but they are appa- 

 rently nearest related to the Oscillatoriaceous 

 Algae. They are very different, however, 

 from SPIRULINA, to which they have been 

 compared. Spirillum bryozoon consists of 

 the spermatozoids of Mosses. 



1. S. tenue. Filament slightly tortuous, 

 indistinctly jointed ; spiral of three or four 



turns; movement active; length 1-1000"; 

 diam. 1-12,000". 



2. S. undula. Filament very tortuous, 

 distinctly jointed ; spiral of one or one and a 

 half turns; length 1-1500"; diam. 1-20,000". 



3. S. volutans (PL 3. fig. 23). Filaments 

 very tortuous, distinctly jointed; spiral of 

 three, four, or more turns; length 1-1400"; 

 diam. 1-14,000". 



4. S.plicatile (Spirochceta plicatilis, Ehr.) 

 (PL 3. fig. 22). Filament very long; coils 

 very numerous ; movement undulating ; 

 length 1-180"; diam. 1-12,000". 



BIBL. Ehrenb. Infus. p. 84 ; Dujardin, 

 In/us, p. 223. 



SPIROCH^TA, Ehr. S. plicatilis = 

 Spirillum plicatile. 



SPIROCHONA., Stein. A genus of In- 

 fusoria, of the family Vorticellina. 



5. gemmipara (PL 25. fig. 35) is found 

 upon the branchial plates of Gammarus pu- 

 lex, where also its remarkable Adneta-form 

 (PL 35. fig. 36) occurs. 



S. Scheutenii is met with upon the feathery 

 setae arising from the terminal joints of the 

 post-abdominal legs of Gammarus. 



BIBL. Stein, Die Infus. 



SPIRODISCUS, Ehr. Under the name 

 S. fulvus, Ehrenberg places among the Infu- 

 soria, in the family Vibrionia, a brownish 

 organism, consisting of a short discoidal or 

 much flattened helical spiral, 1-1200" in dia- 

 meter, and found in Siberia. It exhibited a 

 slow movement. Ehrenberg's figure greatly 

 resembles that in PL 32. fig. 34 (the upper 

 two), without the cilia, and magnified 200 

 instead of 400 diameters. 



BIBL. Ehrenberg, Infus. p. 86. 



SPIROGYRA (Zygnema, Agardh in part) 

 (fig. 673). A genus of Zygnemaceae(Confer- 

 void Algae), mostly very elegant and all very 

 interesting on account of their structure and 

 modes of development. They are green 

 filaments, floating unattached in standing 

 fresh water. They consist of jointed tubes 

 (that is, rows of cylindrical cells), sometimes 

 of considerable size, in the interior of which 

 the green colouring matter is arranged in 

 one or more spiral lines running round the 

 walls, these spiral lines presenting bright 

 points at intervals along their course (PL 5. 

 figs. 17, 26, 27). The green lines consist 

 of bands of protoplasm coloured green by 

 chlorophyll; the bright points are in some 

 stages composed of globules of similar sub- 

 stance, but generally they are occupied by 

 starch-granules imbedded in the protoplasm; 

 smaller starch-granules also occur at certain 



