CHEMICAL REACTIONS. [ 1C5 ] 



CHILODON. 



CHEMICAL REACTIONS. INTRO- 

 DUCTION, p. xlii. 



CHEMISTRY. The following works 

 may be found useful for study or reference 

 in regard to chemical subjects: Stockardt, 

 Exper. Chem. ; Grnelin, Handbueh ; Rose, 

 Anal. Chem. ; Will, Chem. Analyse ; Fre- 

 senius, Anal. Chem. ; Heintz, Zoochemie ; 

 Gorup-Besanez, Zooch. Anal. ; Schmidt, 

 Entw. ein. allg. Untersuchungsmethode ; 

 Hoppe-Seyler, Tr. d'anal. chim. phys. et 

 path. ; Miller, Chem. ; Watts, Diet. ; Roscoe, 

 Lessons #<?., and his larger work ; Engel. 

 Chim. med. et biol. ; Mehu, Chem. med. ; 

 Ralfe, Demonstr. in phys. and path. chem. 



The progress of chemistry is reported in 

 the ' Chemical News.' 



CHEY'LETUS, Latreille. A genus of 

 Acarina (Arachuida), of the family Trom- 

 bidina. 



Char. Rostrum prominent, palpi very 

 thick, resembling arms, and falciform at the 

 ends ; antennal forceps (mandibles ?) didac- 

 tylous ; tarsi with 2 simple claws. Koch 

 describes 6 species ; Michael and Megnin 

 add others. 



C. eruditus (PL 53. fig. 13). Found in 

 books and museums. Parthenogenesis has 

 been found to occur in this species (Beck). 

 C. parasitivorus, found at the root of the 

 hairs of rabbits, feeding upon Listrophori ; 

 C. heteropalpus, on the feathers of the Co- 

 lumbidse &c. ; C. macronychus, on the fea- 

 thers of Insessores ; C. venustissimus, on 

 fodder in a stable ; and C.Jlabellifer, on the 

 walls of a beer-cellar (Michael). 



BIBL. Geryais, Walckenaer's Aptei'es, iii.; 

 Koch, Dentsch. Crvstac. fyc. ; Robin, J. de 

 VAnat. 1867 (figs.), p. 506 ; Beck, Mic. Tr. 

 1866, 30 ; Murray, EC. Ent. 285 ; Michael, 

 Jn. Mic. Soc. 1878, 133 & 313 (figs.); 

 Megnin, Parasites, 1880, 240. 



CHICKWEED, Stellaria media. This 

 common plant is of great interest to the 

 microscopic observer, on account of the 

 facility with which the embryo-sac may be 

 dissected out. See Griffith, Text-book, 45, 

 pi. 1. 



CHICORY. This substance, used for 

 mixing with or adulterating coffee, consists 

 of the roots of the plant of the same name 

 ( Cichonum Intybus). The structures com- 

 posing the root (PI. 2. fig. 6) are recognizable 

 after it has been roasted and ground, con- 

 sisting of membranous cellular tissue, c, 

 short-jointed reticulated ducts of large size, 

 b, and laticiferous tubes, a. Pure chicory 

 does not appear to contain any starch-gra- 



nules, this substance being replaced by inu- 

 line in most of the plants of this family. 

 The presence of starch, therefore, in samples 

 of chicory denotes adulteration, which, when 

 effected by roasted corn or beans, is easily 

 detected ; and the integuments of roasted 

 grain may often be identified. Other com- 

 mon adulterations are roasted carrots, par- 

 snips, or mangel-wurzel : the first of these 

 is difficult to detect, as the structure of the 

 roots is very similar, as is the case to some 

 extent with the parsnip, in which, however, 

 traces of the starch usually remain; the 

 parenchymatous tissue of mangel-wurzel is 

 formed of cells very much larger than those 

 of chicory. In addition to the above, certain 

 substances containing astringent or colour- 

 ing-matters are occasionally found in ground 

 chicory and coffee such as oak-bark and 

 tan, mahogany and other kinds of sawdust. 

 These are easily detected by the micro- 

 scope, from the presence of woody fibre and 

 liber-cells, the origin of which is often to 

 be made out by careful comparative exa- 

 mination. 



BIBL. Hassall, Food and its Adulterations, 

 108, 199, 352. 



CHI'LODON, Ehr. A genus of Infu- 

 soria, of the family Trachelina. 



Char. Body covered with cilia ; mouth 

 with teeth arranged in the form of a tube ; 

 fore part of the head produced into a broad 

 membranous or ear-like lip. 



The cilia form longitudinal rows. 



C. cucidlulus (PI. 30. fig. 27). De- 

 pressed, oblong, colourless, rounded at the 

 ends, slightly auriculate or beaked ante- 

 riorly on the right side; freshwater and 

 marine ; length 1-1120 to 1-140 '. (PL 30. 

 fig. 27 bj side view.) Contains a red eye- 

 spot. 



C. undnatus. Depressed, oblong, rounded 

 at the ends, colourless ; narrowed and curved 

 anteriorly so as to appear hooked ; fresh w. ; 

 length 1-430". 



C. aureus. Ovate-conical, turgid, golden- 

 yellow, anterior end curved so as to form 

 an obtuse beak, posterior end narrowed ; 

 aquatic ; length 1-140". A Nassula (?). 



C. ornatus. Ovato-cylindrical, golden- 

 yellow, ends rounded, a violet spot at the 

 neck ; aquatic and marine ; length 1-174". 

 A Nassula (?). 



Dujardin admits only the first species; 

 referring the others to the genus Nassida. 



BIBL. Ehr. In/us. 336; Duj. Inf. 490; 

 Stein, Inf. &c. ; Claparede and Lachmann. 

 Inf. 335. 



