COB^A. 



[ 180 ] 



COCCOCHLOPJS. 



hands is as follows. The coal is macerated 

 for about a week in a solution of carbonate 

 of potash; at the end of that time it is 

 possible to cut tolerably thin slices with a 

 razor. These slices are then placed in a 

 watch-glass with strong nitric acid, covered 

 and gently heated ; they soon turn brownish, 

 then yellow, when the process must be ar- 

 rested by dropping the whole into a saucer 

 of cold water, or else the coal would be 

 dissolved. The slices thus treated appear 

 of a darkish amber colour, very transparent, 

 and exhibit the structure, when existing, 

 most clearly. We have obtained longitu- 

 dinal and transverse sections of Coniferous 

 wood from various coals in this way ; al- 

 though this structure is most abundant in 

 lignites. The specimens are best preserved 

 in glycerine, in cells ; for spirit renders them 

 opaque, and even Canada balsam has the 

 same defect. Schulze states that he has 

 produced the cellulose reaction with iodine, 

 in coal treated with nitric acid and chlorate 

 of potash. 



The proper identification of vegetable 

 structures in coal must of course depend 

 upon a sufficient knowledge of the charac- 

 ters of vegetable tissues and organisms being 

 possessed by the observer. 



BIBL. Witham, Fossil Vegetables, Ediub. 

 1833 j Link, Abh. Berl. Akad. 1838 ; 34 ; 

 Goppert, Preisschrift ub. Steinkohle.n, Leiden, 

 1848; Lindley and Hutton, Fossil Fl.; 

 Schleiden and Schmidt, Geognost. Verlidltn. 

 des Saalthales, Leipzig, 1846 j Ehrenberg 

 and Schulze, Berlin Ber. 1844; F. Schulze, 

 ibid. 1855 ; Ann. N. H. xvi. p. 69 ; Bailey 

 (Anthracite}, Ann. N. H. xviii. 67; Unger, 

 Gen. et Spec. Plant. Foss. 1850 ; Oarruthers, 

 Mn.Mic. Jn. ii. 377, 225, iii. 144; Wil- 

 liamson, ibid. ii. 66 ; Lyell, Princip. of Geol.; 

 Huxley, Contemp. Rev. 1867; Dawson, 

 Acadian Geol 1868 ; Mn. Mic. Jn. 1870, 

 319; Williamson, Phil. Proc. $ Trans. 

 1873 et seq. ; Zirkel, Mineral**, 1873, 257 j 

 Reinsch, SteinkoMe, 1881. 



COB^E'A, Cuv. A climbing Dicotyledo- 

 nous plant, of the Nat. Order Polemomacese, 

 common in cultivation, remarkable for the 

 curious pyriform cells upon its seeds, con- 

 taining a spiral fibre (PL 28. fig. 20). See 

 SPIRAL STRUCTURES. 



COCCID'IUM. A form of fructification 

 in the FLORTDEJE. 



COCCINEL'LA, Linn. (Lady-bird). A 

 genus of Insects, of the order Coleoptera, 

 and family Coccinellidse. 



C. septenipunctata } the common lady-bird. 



This insect exhibits the circulation through 

 the elytra. If one of these is separated 

 from the body without being detached, and 

 arranged in such a manner that it may be 

 viewed as a transparent object, slow and 

 uniform continuous currents, one ascending 

 and the other descending, will be seen be- 

 tween the lamina of which the elytrum 

 consists. On dividing the latter an amber 

 transparent liquid containing colour] ess glo- 

 bules escapes. 



BIBL. Nicolet, Ann. Sc. Nat. 3 s6r. vii. ; 

 Westwood, Introd. fyc. : Curtis, Brit. Ent. 

 208 ; Stephens, Brit. Entom. ; Calver, Ka- 

 ferbuch, 690. 



COCCOBACTE'RIA .. A term employed 

 byBillroth to designate the Schizomycetous 

 Bacteria and their allies. The author re- 

 gards the globular forms Coccos, and the 

 rod-like forms Bacterium and Bacillus, as 

 belonging to a single organism ; the former 

 arising from the division and spore-formation 

 of the latter, and the two forms being often 

 found in the same filament or zooglcea-form ; 

 the whole constituting his Coccobacteria 

 septica. Billroth gives new names to the 

 various forms, and regards them as colour- 

 less parallel states of many of the lower 

 Algae. The occurrence of these organisms 

 in various liquids, and their influence in the 

 production of decomposition and disease, 

 are fully treated in his elaborate and well- 

 illustrated treatise. (Billroth, Coccobacteria 

 septica, 1874.) 



COCCOCAR'PE^E (Algse). See CRYP- 



TONEMIACE^J. 



COCCOCAR'PIA, Pers. A small genus 

 of mostly tropical Lichens, now united with 

 Pannaria. 



C. (P.) plumbea, Lightf., is British, and 

 has the thallus orbicular, livido-cinerascent, 

 adnate ; apothecia reddish-brown ; spores 8, 

 simple. 



BIBL. Lightfoot, Fl. Scot. ii. 826, pi. 26 j 

 Leighton, Lich-FL G. B. 154. 



COCCOCHLO'RIS, Sprengel (Palmo- 

 glcea, Kiitz). A genus of Palmellaceee 

 (Confervoid Algse), consisting of green mi- 

 croscopic cells, oval or globular, imbedded 

 in a gelatinous matrix, which is at first de- 

 finite in form (thus differing from Palmella}, 

 subsequently effused and shapeless. The 

 green cells are vesicles, filled with granular 

 colouring-matter (chlorophyll) when in 

 active vegetation. They multiply by divi- 

 sion ; and besides this, some of them grow 

 much larger than the rest, and their con- 

 tents are converted into a number of cells ; 



