CONIOPHYTUM. 



[ 204 ] 



COXJUGATION. 



London Journ. of Bot. iii. 320; Tulasne, 

 Compt. Remhis, 'March 1851 {Ann. N. H. 

 1851, viii. 114) ; Ann. So. Nat. 3 S(5r. xv. 

 370, XX. 129, 4 ser. ii. 77, v. p. 108 ; Botan. 

 Zeit. xi. 49; Compt. Rend. 1854 {Ann. N. 

 H. 2 ser. 1854, 715) ; Fries, St/sf. Mijcol ; 

 De Bary, Brand-Pihe, Berlin, 1853. 



CONIO'PPIYTUM, Hassall {Dolicho- 

 spermiim, Ralfs). — A genus of Nostocha- 

 cese (Coufervoid xAlgte), consisting of one 

 species ; colouring large sheets of water of 

 a deep coppery green, by its minute fronds, 

 each composed of a number of filaments 

 variously curled and interwoven, densely in 

 the centre, and more loosely towards the 

 circumference ; these fronds being free, look 

 like a pulverulent or granular accumulation 

 in the water, when viewed by the naked 

 eye. The genus differs from its allies in 

 the relative positions of the spermatic and 

 vesicular cells, the former being either 

 next to, or at a distance from the latter. 

 This fact seems to throw some doubt on 

 the value of this character as a distinctive 

 mark. 



a Thompson!; Ralfs (PI. 3. fig. 9), = Z)o- 

 Uchospermnm Thomp., Ralfs, Ann. N. H. 

 1850, v. 33(3, pi. 9. fig. 3. Anahainn Flos- 

 aqitcs, Harvey, Brif. Algce, ed. 1 ; Hassall, 

 Algce, pi. 75. f. 2 ; also Bot. Gaz. 1850 

 {Colour of the Serpentine?). 



COXIOTHE'CIUM, Corda.— Anobscure 

 genus of Torulacei (Couiomycetous Fungi) ; 

 the so-called species being probably forms 

 of some other Fungi. 



C. amentacearum is extremely common 

 on dead wiUow-twigs. 



BiBL. Berk, and Broome, Ann. N. H. 

 1850, V. 460 ; Corda, Ic. Fiinc/. i. figs. 21, 

 25, 2G ; Fries, Smnma Veqet. 523. 



CONIOTHY'RIUM, Corda.— A genus of 

 Sphaeronemei (Stylosporous Fungi). 



C. ylomeratum, Corda, recorded by Berke- 

 ley and Broome as British, is said by Fries 

 to' belong to his genus Cliaosporwn. It is a 

 microscopic plant growing in the cracks of 

 dead wood (elm) ; composed of minute free 

 membranous peridia enclosing numerous 

 spores, which escape by the bursting of the 

 apex. 



BiBL. Berk, and Broome, Ann. N. H. 

 1854, xiii. 400; .Corda, iv. f. 208; Fries, 

 Siimma Veget. 522 ; Montague, Ann. Sc. 

 Nat. 3 p.5r. xii. 304. 



CONJUGATION or ZYGO'SIS. — A 

 process occurring among many of the lower 

 plants and animals, in which the substance 

 of two distinct organisms comes into con- 



tact and becomes fused into a single mass, or 

 zj'gospore. This operation is always con- 

 nected with reproduction in plants, some- 

 times also in animals. 



In the vegetable kingdom it has been ob- 

 served in the Algae, viz. in the Zygnemaceae, 

 the Desmidiacepe, the Diatomacete, the Pal- 

 mellaceag, and in the genus Si/zygites of 

 Fungi; also in the Myxomycetes. It also 

 occurs in the zoospores. In all these cases 

 it consists essentially in the blending to- 

 gether of the contents of two distinct cells : 

 either by the complete fusion of two free 

 cells ; by the passage of the contents of 

 one cell into the cavity of another through 

 newly-formed connecting tubes ; or by the 

 emission of the contents of both cells into 

 a space between them, where the mixed 

 contents become enclosed in a special en- 

 A'elope. 



The conjugation ear- 

 liest discovered was that 

 of the Zygnemacese, 

 which the cells of dis- 

 tinct filaments lying pa- 

 rallel with one another, 

 become united by late- 

 ral inosculation or by 

 cross branches, formed 

 by the budding out of 

 the walls of the cells 

 opposite to each other, 

 the protruded processes 

 coming into contact, co- 

 hering and bscoming 

 confluent by tlie absorp- 

 tion of the surfaces of 

 contact (fig. 137). The 

 cavities of the two cells 

 opened into one another, the contents be- 

 come mixed ; in Spiro- 

 gyra and Zygnema the 

 contents of one of the 

 cells usually travel 

 across into the cavit}' of 

 the other (P1.9. tig. 18); \ 

 in Zygogoniinn the con- 

 tents of both cells collect 

 in the cross-piece, this 

 is the case also in Meso- 

 carpus (fig. 138) and 

 StaUrocarpits, in the lat- 

 ter of which the cross- 



Zygnema cruciata. 

 Conjug-itin^ filaments. 

 Magnified 250 dia- 

 meters. 



being thus freely 



piece 

 enlarged. 



becomes greath" 

 The contents 

 in all these cases be- 

 come retracted from the 

 cell-wall, and, secreting 



, Mesocarpus scalaris. 

 Conjugating filaments 

 with spores. 

 Jlagnifled 200 dia- 

 meters. 



