CYSTOPUS. 



[ 186 1 



CYTHERE. 



Cystopterideae (Polypodgeous Ferns), con- 

 Fig. 157. 



Cystopteris fragilis. 



A pinnule with the sori covered by the indusia. 



Magnified 10 diameters. 



taining several elegant little indigenous 

 species (fig. 15/). 



CYSTOPUS, Leveille. — A genus of 

 Cseomacei (Coniomycetous Fungi), of which 

 the ' white rust ' common on cabbages and 

 other Cruciferous plants is a good example, 

 appearing in white pustules, eventually 

 bursting and destroying the epidermis of the 

 leaves, stalks, flowers and seed-vessels of 

 the infected plants. When fine slices of 

 these pustules are examined under the 

 microscope, the mycelium is found, creep- 

 ing among the cells of the parenchyma, 

 composed of inarticulate, tubular, branched 

 filaments, with a colourless membrane and 

 whitish granular contents. Numerous rami- 

 fications spread out in the plane of the 

 epidermis, while others spring up in tufts of 

 two to seven, or rarely singly, perpendi- 

 cular to the former, to produce spores. 

 These erect branches are at first mere 

 pouches projecting from the horizontal fila- 

 ments ; they gradually swell into ovate- 

 cylindrical or club-shaped sacs. The con- 

 tents in the summit of each such sac become 

 organized into a spore, which at length 

 quite fills up the top of the sac (sporange). 

 Then the sac or sporange becomes con- 

 stricted under this first sj)ore, and the for- 

 mation of a second commences under the 

 constriction. This is repeated until a neck- 

 lace-like chain of spores is produced, the 

 spores subsequently becoming somewhat 

 cylindrical or cubical. The number ap])ears 

 indefinite -, five and seven spores have been 

 found in a chain ; they are united by the 

 constricted portions of the sporange ; and 

 even when they have fallen apart, these 

 connecting pieces are seen projecting on them 



like parts of a stalk from which they have 

 been broken off. Both the adherent spo- 

 rangial membrane and the smooth proper 

 coat of the spores are colourless, the contents 

 granular and whitish. Tulasne has recently 

 discovered another form of spore, spheroidal 

 or trigonal, and of a yellow colour, only one 

 or two of which are formed from the end of 

 a fertile filament. See Uredine^. Br. 

 species : 



C. candidus, Lev. Very common on 

 Cruciferse, producing great distortion in the 

 growth. Uredo Candida, Pers., Grev. Sc. 

 Crypt. Fl. t. 251. 



BiBL. heveiWe, Ann. des Sc.nat. 3 ser. viii. 

 369 j Berkeley, Hort. Transact, iii. 265 

 (figs.); De Bary, Brajidpilze, Berlin, 1853, 

 p. 20. pi. 2. figs. 3-7 ; Tulasne, Ann. des 

 Sc. nat. 4 ser. ii. 108, 171. 



CYSTOSEIRA, Ag.— A genus of Fucaceje 

 (Fucoid Algse), of much branched habit, 

 some species of which are common on rocks 

 in tide-pools or between tide-marks. The 

 gradually attenuated branches contain in- 

 flated air-sacs, at intervals along their length, 

 within their substance. The conceptacles 

 are immersed in the ends of the branches, 

 which are pierced by their numerous pores. 

 They contain both spores and antheridia, 

 but not mixed ; the spores occur at the bot- 

 tom of the cavity, the antheridia above, near 

 the pore. The antheridia have only a single 

 coat. The autherozoids are expelled in a 

 mass, and soon after begin to move, turning 

 rapidly upon their axes. They are oval or 

 spherical in one du-ection, and rather com- 

 pressed in the other. Thev have two cilia 

 mserted on a red granule ; the long cilium 

 in front moves rapidly, while the posterior 

 short one is motionless. See Fucace^. 



BiBL. Harvey, Br. Mar. Alg. pi. 1 B; 

 Phyc. Brit. 1 33, &c. ; Thuret, Ann. des Sc. 

 nat. 3 ser. xvi. pp. 7 & 10. 



CYSTOTRICHA, Berk, and Broome.— A 

 genus of Phragmotrichacei (?) (Coniomyce- 

 tous Fungi). Minute fungi forming dots or 

 lines upon wood from which the bark has 

 been stripped. Only one species is de- 

 scribed. 



C. striola, Berk. & Br. Perithecia black, 

 with a reddish tinge, opening by a reddish 

 disk. 



BiBL. Berk. & Br. Ann. Nat. Hist. 2 ser, 

 V. 457. pi. 12. fig. 10. 



CYTHERE, MiilL— A genus of Entomo- 

 straca, of the order Ostracoda, and family 

 Cytheridse. 



Char. Eye single ; superior antennae sim- 



