CILIA. 



[ 144 ] 



CIMEX. 



solution of potash excites the movement of 

 animal cilia after it has become languid. 



The detection of the cilia is frequently of 

 great importance, as the characters of Infu- 

 soria, &c. are often based upon their num- 

 ber and arrangement. The means are either 

 indirect, as by the addition of moistened 

 particles of colouring matters, as indigo, &c. 

 to the living organism, and watching for 

 the movements of the particles ; or direct, by 

 examining the structures after the addition of 

 solution of iodine or bichloride of mercury, 

 or di-ying them at a gentle heat. Both me- 

 thods should be adopted to check each other, 

 for molecular movement has some resem- 

 blance to ciliary motion when feeble, although 

 there is absence of a definite current; and 

 fine hair-like Algse or Fungi attached to aqua- 

 tic organisms often resemble cilia, but are 

 deficient in the motion. 



See Infusoria, Membranes, undu- 

 lating, and Molecular motion. 



BiBL. Purkinje & Valentin, Comm. PJiys. 

 Sfc; Sharpey, Todd's Cycl. of Anat. Sf Phys. 

 i. 606 ; Valentin, Wagner' sHandw. d. Phys. 

 ^c. i. 484; Virchow, Archiv, vi. p. 133. 



CILIA of Vegetables. — These minute 

 vibratile threads, apparently of the same 

 (unknown) nature as those of animals, are 

 in all cases met with in connexion with the 

 protoplasmic or nitrogenous structures of 

 plants, the structure bearing the closest re- 

 lation to animal organization. Cilia have as 

 yet been found only in Flowerless Plants, 

 viz. in all the higher or stem-forming Cryp- 

 togams, and in the Algae among the Thallo- 

 phytes. In the Marsileaceae, Lycopodiaceae, 

 Ferns, Equisetacea3, Mosses, Hepaticaceae, 

 and Characese, they are found upon the ac- 

 tive filaments (spermatozoids) discharged 

 from the antheridia. In the Algae they oc- 

 cur upon the zoospores or active gonidia, 

 and on the fully-developed plants of the fa- 

 mily Volvocineae. They have been stated to 

 occur in certain other complete organisms, 

 as in Closterium, but this statement requires 

 fm'ther confirmation. Rigid filaments bearing 

 some resemblance to cilia occur occasionally 

 upon Diatomaceae and Oscillatoriae, but these 

 are not vibratile organs. The mode of ar- 

 rangement, &c. varies considerably among 

 the cases above cited. In spermatozoids 

 of the Marsileaceae, Lycopodiaceae, Ferns, 

 and Equisetaceae, they are set in considerable 

 number along a filament spirally or heliacally 

 coiled (PI. 32. fig. 34). In the Muscaceae, 

 Hepaticaceae, and Characeae, a pair of very 

 long ciha are attached at one end of the fila- 



ment(fig.l27.p.l34). In zoospores they occur 

 in either a pair at the apex, as in Protococcus, 

 Conferva, Cladophora, Codium, &c., or there 

 are four in the same situation, as in Ulothrix, 

 Chcetophora, Ulva, &c.; while the large zoo- 

 spores of (Edogonium bear a crown of vibra- 

 tile cilia, and the great elliptical zoospore of 

 Vaucheria is clothed with them over its 

 whole surface. In the Volvocineae, there is 

 a pair of cilia attached, just like those of 

 zoospores, to each member of the family of 

 which the compound organism is made up, 

 and these project through orifices in the 

 common envelope, so as to render the per- 

 fect plant locomotive; while the cilia of 

 ordinary zoospores disappear when they be- 

 come encysted in a cellulose coat, prepara- 

 tory to germination. In the Fucaceae, as 

 in Fucus, Ectocarpus, Laminaria, &c., the 

 zoospores produced in the trichosporangia, 

 have a different arrangement of the cilia; 

 there are always two, but they are attached 

 on a reddish point on the side of the zoo- 

 spore, not at its apex, and one of the cilia is 

 directedforwards from the apex or beak, while 

 the other trails behind like a kind of rudder. 



The mode in which these transitory cilia 

 are lost is variously stated; some authors 

 think they are retracted into the protoplasm; 

 from what we have seen, we believe they are 

 thrown off entire. The cilia have the same 

 chemical reactions as the protoplasmic sub- 

 stances generally, and are apparently pro- 

 cesses of it; they are stained brown by 

 iodine, which also stops their motion and 

 renders them partly solid. The mode of 

 detecting and observing cilia is given in the 

 preceding article. Further particulars of 

 individual cases will be found under the 

 heads of the families and genera named above. 



BiBL. Thuret, Rech. sur les Zoosjyores des 



Algues, Sfc, Ann. des Sc. nat. 3 ser. vols. xiv. 



& xvi.; Note sur les Antheridies des Fougeres, 



Ann. des Sc. nat. 3 ser. xi. 5 ; Hofmeister, 



Vergleichenden Untersuchungen, Sfc. Leipsic, 



1851 ; Unger, Die Pflanze in Momente der 



Thierwerdung, p. 34. Vienna, 1843; Al. 



Braun, Verjungung, Sf-c. {Rejuvenescence ^c, 



Ray Soc. Vol. 1853); Cohn, Protococcus 



pluvialis, Nova Acta A. L. C. C. xxii. 735 



{Ray Soc.Vol. 1853. p. 352 etseq.); on Ste- 



phanosphcera, Siebold & KoUiker's Zeitschr. 



iv. 77, transl. Ann. Nat. Hist. 2 ser. x. 321 



etseq.; Henfrey, On Ferns, Linn. Trans, xxi.; 



Focke, Physiologische Studien. 



CILIARY PROCESSES. See Eye. 



CIMEX, Linn. (Bug). — A genus of 

 Insects, of the order Hemiptera (Hete- 



