STAURASTRUM. 



[ 613 ] 



STAURONEIS. 



Starch-granules are usually isolated by 

 slicing the tissues in which they exist, and 

 washing them out. When they are to be 

 observed in situ, either delicate transparent 

 structures (as in the Cryptogamia) must be 

 selected, or sections very carefully made. 

 The cells filled with starch of the potato (PL 

 36. fig. 20), &c., may be isolated by macera- 

 ting the structures in water for a day or two. 

 Starch-granules may be preserved for a 

 certain time in glycerine, but they are, per- 

 haps, best taken fresh from a store of dry 

 granules when required for examination. 



BiBL. Rapport sur Payen, Persoz, 4*c., 

 Memoires des savans etrangers {Paris Acad.), 

 v.; Poggendorff, Annal. d. Chem. u. Pharm. 

 xxxvii. p. 114 (1836); Fritzsche, ibid, xxxii. 

 p. 129 (1834); Payen, Ann. des Sc. nat. 

 2 ser. x. p. 5, Mem. Paris Acad. viii. p. 209; 

 Meyen, PJlanzenjjhi/s. i. p. 189 ; Miilder, 

 Physiol. Chemist. (Edinburgh, 1849), p. 208; 

 BischofF, Bot. Zeit. ii. p. 385 (1844); Munter, 

 iii. p. 193 (1845); C. Mliller, ibid. 833 (Ann. 

 Nat. Hist. xvii. p. 73); Nageli, Zeitschr.f. 

 Wiss. Bot. p. 149 (1844), iii. p. 117 (1846), 

 Ann. Nat. Hist. xvii. p. 185, Ray Soc. 

 Vol. 1849. p. 183; Schleiden, Grundz. der 

 Bot. 3rd ed. p. 177 {Principles, p. 10); 

 Mohl, Vegetable Cell (London, 1852), p. 44, 

 Vermischt. Schrift. p. 449, Ann. Nat. Hist. 

 2nd ser. xv. p. 371 ; Martin, Phil. Mag. 

 2nd ser. iii. p. 277; Busk, Microsc. Trans. 

 2nd ser. i. p. 58 ; AUman, Mic. Journ. ii. 

 p. 163; Criiger, Bot. Zeit. xii. p. 41 (1854) 

 {Mic. Journal, ii. p. 173) ; Kiitzing, Grundz. 

 d. Phil. Bot. i. p. 261 ; Lindley, Introd. to 

 Botany, 2nd ed. p. Ill; E. Quekett, Ann. 

 Nat. Hist. xvii. p. 193; Raspail, Ann. des 

 Sc. nat. vi. (1825) and vii. (1826). 



STAURASTRUM, Meyen.— A genus of 

 Desmidiaceae. 



Char. Cells single, constricted at the 

 middle ; end view angular or circular, with a 

 lobato-radiate margin, or rarely compressed 

 with a process at each end. 



Sporangia generally spinous and often 

 globose. 



Thirty-eight British species (Ralfs). 



S. dejectum (PI. 10. fig. 26). Segments 

 smooth, lunate or elliptical, constricted por- 

 tion very short ; end view with inflated 

 awned lobes. Common; length 1-830". 



(S. margaritaceum (PI. 10. figs. 28, 29). 

 Segments rough, tapering at the constriction, 

 and with short lateral processes ; end view 

 with five or more short, narrow, obtuse rays. 

 Length 1-1176". 



S. gracile (PI. 10. tig. 30). Segments 



rough, elongated on each side into a slender 

 process terminated by minute spines; end 

 view biradiate. Length 1-770 to 1-540". 



BiBL. Ralfs, Brit. Desmidiacece, 119. 



STAUROCARPUS, Hassall {Staurosper- 

 muni, Kiitz.). — A genus of Zygnemacese 

 (Confervoid Algae), growing in (boggy) 

 freshwater pools ; distinguished by the re- 

 markable quath-ate spore formed in the 

 cross-branch produced by conjugation. Has- 

 sall enumerates six species. He speaks of, 

 but does not describe or figure the spores of 

 S. ccerulescens filled with " zoospores." 

 Thwaites, however, saw the spores of S. 

 gracilis resolved into four portions, and 

 therefore until this body has been seen to 

 germinate, perhaps it should be regarded as 

 a sporange. Probably, however, the condi- 

 tions are the same as in Spirogyra. 



1. aS. glutinosus. Filaments 1-1800 to 

 1-1560'' in diameter, bluish-green, lubricous ; 

 spores four-sided, with the angles rounded 

 (Hass. pi. 47. fig. 1). 



2. S. ccerulescens. Filaments about the 

 same size as the last; spores cruciate, with 

 obtuse lobes (Hass. pi. 47. fig. 2). 



3. aS. quadraius. Filaments 1-2400" in 

 diameter, spores between square and globose 

 (Hass. pi. 48. fig. 1). 



4. S. virescens. Filaments 1-3240 to 

 1-3000" in dia- 

 meter; spores cru- 

 ciate, emarginate 

 (Hass. pi. 48. fig. 2). 



5. (S. gracillimus. 

 Filaments 1-4200 to 

 1-3960" in diame- 

 ter ; spores acutely 

 quadrangular (Hass. 

 pi. 49. fig. 2). 



6. /S. gracilis 

 (fig. 699 and PL 5. 

 fig. 16). Filaments 

 thicker than in S. 

 gracillimus ; spores 

 cruciform (Hass. 49. 

 fig. 1). Perhaps the 

 same as the preceding. 



BiBL. Hassall, Brit. Fr. Alg. p. 176; 

 Kiitzing, Sp. Alg. p. 437, Tab. Phyc. v. pis. 8 

 & 9 ; Thwaites, An7i. Nat. Hist. xvii. p. 262 ; 

 Ralfs, Brit. Desmidie(B, p. 146 ; Al. Braun, 

 Verjungung, Sfc. {Ray Soc. Vol. 1853. p. 287). 



STAURONEIS, Ehr.— A genus of Dia- 

 tomaceae. 



Char. Frustules resembling those of Na- 

 vicula, but the median nodule expanded into 

 a transverse band or stauros. 



Fig. 699. 



Staurocarpus gracilis. 



Conjugating filaments with 

 spores (or sporanges). 



Magnified 100 diameters. 



