CLADOBOTRYUM. 



[ 146 ] 



CLADOSPOR1UM. 



covered with hairs. The animals protrude 

 these filaments incessantly from the orifice 

 of the shell, and retract them, whereby wa- 

 ter for respiration, and, with the water, food 

 is brought into the shell. Cirripeds are 

 hermaphrodite . 



The young Cirripeds, after leaving the 

 ovum, resemble some of the Entomostraca 

 (Cyclops, Cypris). They are unattached, 

 and possess eyes. 



BIBL. Cuvier, Mem. du Mus. d'Hist. Nat. 

 ii. 1815; Saint-Ange, Mem. s. I. Cirrip.-, 

 Coldstream, Todd's Cycl. Anat. and Phys., 

 art. Cirrhopoda ; Burmeister, Beit. z. Gesch. 

 d. Rankenfusser ; J. V. Thompson, Zool. 

 Researches, and Phil Trans. 1835, p. 355 ; 

 Darwin, Monograph of the Cirripedia, Ray 

 Society's Publ. 1851 and 1853; Bibl. of 

 ANIMAL KINGDOM. 



CLADOBOTRYUM, Nees. See DAC- 



TYLIUM. 



CLADONIA, Fee. A genus of Lecidineee 

 (Gymnocarpous Lichens), with a somewhat 

 shrubby thallus, abundant on moors and 

 heaths. The Rein-deer Moss ( C. ranaiferina) 

 is common in such localities. 



BIBL. Hook. Brit. Fl. ii. pt. 1. 238; 

 Engl. Bot. pi. 173, 174, &c. 



CLADOPHORA, Kiitz. A genus of 

 Confervaceae(ConfervoidAlg8e),distmguished 

 by the branched habit of the attached fila- 

 ments. The Cladophorfe are interesting in 

 many respects, in particular for the thick, 

 laminated structure of the cell-wall, the spe- 

 cial projecting orifice in this by which the 

 zoospores are discharged, the large number 

 of the zoospores, and, lastly, by the favour- 

 able opportunity they afford of observing 

 cell-division in the growth of the branched 

 filaments. The filaments are composed of 

 cylindrical cells attached end to end, from 

 which the branches arise by the gradual pro- 

 trusion of a cylindrical pouch near the upper 

 end, which pouch, becoming shut off by a 

 septum, forms the first cell of the branch. 

 The cellulose wall acquires repeated layers 

 of thickening with age, and longitudinal and 

 transverse striae may be detected in these by 

 careful management. (See SPIRAL STRUC- 

 TURES.) The cellulose wall is lined by a 

 layer of protoplasm (primordial utricle), upon 

 the inside of which lies the chlorophyll, not, 

 however, really imbedded in it, as it is often 

 seen retracted from it in the centre of the 

 cell. At certain periods, numerous starch- 

 granules occur in the mass of chlorophyll, 

 but these disappear when the latter is about 

 to subdivide into zoospores. When this 



takes place, the whole mass of chlorophyll is 

 contracted from the wall, and becomes broken 

 up, by a kind of segmentation, into a very 

 large number of 2-ciliated zoospores (these 

 sometimes occur in pairs, through imperfect 

 division). The zoospores, which are pro- 

 duced in all the cells, are discharged through 

 a special papilliform orifice in the cell-wall 

 (PI. 5. fig. 13); they have a distinct red 

 spot. Numerous supposed species inhabit 

 fresh, brackish, or sea-water in Britain; 

 some are very common and abundant ; but 

 it is difficult to draw out differential charac- 

 ters, as the habit appears to be very variable. 

 They are Conferva of older authors. 



1. C. glomerata, Dillw., is 'of a dark green 

 colour, and grows commonly, in long drawn- 

 out skeins, in pure running water; but it 

 seems to be identical with the rarer C. cega- 

 gropila, L., which forms dense balls 2 to 4" 

 in diameter, in lakes, while there is also a 

 marine variety. 



2. C. crispata, Sm., is perhaps not di- 

 stinct; it forms yellowish or dull green 

 strata, everywhere common in fresh water ; 

 frequent in" brackish water. It is the same 

 as C.flavescens, Roth. C.fracta, Fl. Dan., 

 is probably a form of this. 



The commonest marine species, which are 

 often found in large quantities on the sea- 

 shore, remarkable by their bright green tint, 

 are C. rupestris, L., Icetevirens, Dillw., al- 

 bida, Huds., lanosa, Roth., arcta, Dillw., 

 and glaucescens, Griff. ; but some of these, 

 and of the rarer, appear doubtful. The species 

 require a careful study of fresh specimens in 

 all stages. Kiitzing (Sp. Alg.} has made an 

 inextricable mass of confusion of his species. 



BIBL. Hassall, Br. Fr. Alga, p. 213. pi. 

 65-67; Harvey, Br. Mar. Alga, p. 199. 

 pi. 24 D ; Thuret, Rech. sur les Zoospores, 

 fyc., Ann. des Sc. nat. 3 ser. vol. xiv. p. 10. 

 pi. 16; Al. Braun, Verjungung, Sfc.(Rejuv. 

 in Nature, Ray Soc. Vol. 1853) passim-, 

 Mohl, Vermischte Schriften, p. 362. pi. 13. 



CLADOPHYTUM, Leidy. Probably the 

 mycelium of a fungus. Found in the intes- 

 tine of an lulus. 



BIBL. See ARTHROMITUS. 



CLADOSPORIUM, Link. A genus of 

 Dematiei (Hyphomycetous Fungi). The 

 species C. herbarum is one of the commonest 

 moulds upon decaying substances of all sorts; 

 in this the mycelium spreads over the surface 

 as a dense or loose web of confluent tufts of 

 microscopic filaments, straight or curved, 

 more or less varicose, simple or branched ; 

 from these arise chains of spores, simple or 



