CHARACE^E. 



[ 163 ] 



CHEESE-MITE. 



layer is wavy and irregular ; and thus its 

 rotation carries along-, to a certain extent, 

 the watery juice filling up the centre of the 

 cell, in which lie numerous transparent pro- 

 toplasm-vesicles, ciliated bodies, and gra- 

 nular matters. 



The fructification of Chara is very curious, 

 and its homologies are not yet satisfactorily 

 made out. Upon the branches are found 

 bodies of two kinds, either on the same or 

 on different branches, or on different plants ; 

 called the globule and the nucule. The glo- 

 bule (figs. 120, 121) or antheridium is a 

 spherical body, of a red or orange-colour 

 when ripe, presenting a transparent thickish 

 outer coat, enclosing an inner wall of curi- 

 ous construction. This is composed of 

 eight triangular plates, each composed of a 

 number of long wedge-shaped cells radiating 

 from a central cell. The plates have dentate 

 margins, by which they fit into one another 

 (fig. 121). The cells contain a red colour- 

 ing-matter. In the centre of each plate, 

 inside, rises an oblong cell running in to- 

 ward the centre of the globule, where it 

 meets its fellows from the other plates, and 

 they are united by a little collection of sphe- 

 rical cells ; a ninth cell, of similar form but 

 larger size, comes to j oin these in the centre, 

 it being the pedicle of the globule, arising 

 from the branch upon which it is seated, 

 and entering the globule between the lower 

 four valves. At the point where these nine 

 cells meet in the centre, a number of long 

 septate filaments arise (fig. 122). These are 

 composed, when mature, of a large number 

 of cells placed end to end (figs. 122 & 123), 

 each of which finally discharges a ciliated 

 spiral filament (spermatozoid), which swims 

 actively in the water. The globule bursts, 

 by the separation of its triangular valves, 

 when mature ; and it is after this that the 

 spermatozoids are emitted. The form of 

 these spermatozoids is very like that of those 

 found in the Mosses, and different from what 

 is seen in the Ferns, Lycopodiacese, &c. 

 (PI. 40. figs. 31-34). 



The nucule or carpogon of the Chara 

 (figs. 120 & 124) forms an oval body coated 

 by five cells, wound spirally around a central 

 tough sac; the five cells terminating above 

 in five or ten smaller cells, which project like 

 teeth from the summit, forming a kind of 

 crown. The cells of the crown separate from 

 each other at a particular period, leaving a 

 canal leading down to the central cell, which 

 contains protoplasm, oil, and starch- glo- 

 bules. Ultimately the nucule falls off, forms 



a resting-spore, which germinates, and be- 

 comes developed into a new plant. The 

 germinating spore does not, however, di- 

 rectly give origin to the young plant ; but, 

 as in the higher Cryptogamia, a prothallus 

 is first formed, and upon this, the first 

 branches of the plant arise by ordinary 

 gemmation. The prothallus consists of a 

 single row of cells, forming a filament. This 

 is not produced, however, in Nitella. 



The Chara also multiply by gemmas, 

 produced at the articulations of the stem ; 

 of which there are three modifications. 



Carter has published some interesting 

 observations on the development of the root- 

 cells of Chara j also an account of the ab- 

 normal products which are sometimes found 

 in decaying cells. 



BIBL. Corti, Osserv. sutta Circulazione^ 

 1774 ; Amici, Mem. d. Societa to&cma,1818; 

 Ann. d. Sc. N. 1824 ; Dutrochet, Ann. d. Sc. 

 Nat. ser. 2. x. 349; Meyen, Pflanzen-phys. 

 ii. 206 ; Varley, Tr. Soc. Arts, xlix. 1833 ; 

 Micr. Tr. ii. 93, 1849 ; Slack, Tr. Soc. Arts, 

 xlix. ; Thuret, Ann. d. Sc. Nat. 2 ser. xiv. 

 65, 3 se*r. xvi. 18 ; Treviranus, Phys. d. 

 Gewdchse, \. 1839 ; Kiitzing, Phyc. gen. 313 ; 

 C. Miiller, Bot. Zeit. 1845 (Ann. N. H. xvii. 

 254) ; Goppert and Cohn, Bot. Zeit. vii. 665, 

 1849 ; Braun, Ber. Berl. Ak. 1852-3 (Ann. 

 N. H. 2 ser. xii. 297) ; Carter, Ann. N. H. 

 2 ser. xvi. 1, xix. 13 ; Pringsheim, Jahrb. 

 1864; Berk. Suppl. Eng. Bot. t. 2762 ; 

 Nageli, Beit. ii. 1860 ; De Bary, Monatsb. 

 Berl. Ak. 1871 ; Sachs, Bot. 295. 



CHARA'CIUM, Braun. A genus of 

 Confervoid unicellular Algae, of doubtful 

 position ; reproduction by repeated binary 

 division of the endochrome. Allied to Hy- 

 drocytium. Adherent to larger submerged 

 Algae. Perhaps only male spores of CEdo- 

 gonium and allied genera. 



Ra,benhorst describes 13 species. 



C. Sieboldii (PI. 5. fig. 2). On filiform 

 Algae and freshwater mosses. 



BIBL. Rabenhorst, Fl. Alg. iii. 82; Braun, 

 Alg. Umcell. Gen. nova, 1855. 



CHASMATOS'TOMA, Engelmann. A 

 genus of Holotrichous Infusoria. 



Char. Free, ovate or reniform j cilia long, 

 matted ; mouth near the centre of the flat- 

 tened ventral surface, enclosing a minute 

 undulating membrane. 



C. reniforme. Fresh water ; length jl ff ". 



BIBL. Engelmann, Zeitsch. wiss. Zool. 

 1862, ii. ; Kent, Inf. 540. 



CHEESE-MITE. See ACARUS DOMES- 



TICUS. 



