CANNA. 



[ 132 ] 



CAPILLARIES. 



-^A genus of Ostracoda (Entomostraca), 

 family Cvpridse. 



Char. Two pairs of antennae ; superior 

 long, with numerous joints and a pencil of 

 long filaments ; inferior stout and pediform, 

 without a tiift of long hairs or filameuts (see 

 Cypeis) : eye single ; motion creeping only. 

 Five British species ; freshw. 



C. albicans, Br. ; lactea,Bd.; compressa, 

 Koch ; Candida, INIiill. 



BiBL. Baird, Entom. 159 ; Norman, Ann. 

 N. II. 1862, ix. 46; Brady, Linn. Tr. 1868, 

 xxyi. 381. 



CANNA. — A genus of Monocotyledonous 

 plants belonging to the same natural family 

 as the arrow-root (Marantacese), and valu- 

 able from the same cause. Tous-les-mois is 

 a starch derived from the tubers of a Canna, 

 supposed to be C. edulis, Ker. The grains 

 of genuine Tous-Ies-muis have distinctive 

 microscopic characters, as shown in PL 46. 

 fig. 25. 



CANTHAREL'LUS.— A genus of Aga- 

 ricini (Hymenomycetous Fungi), differing 

 from Aqaricusm the vein-like gills. 



CAN'THOCAMPTUS, Baird {Cydops, 

 pt., Miill.).— A genus of Entomostraca, of 

 the order Copepoda, and family Cyclojndae. 



Cha7\ Jaw-feet small, simple; inferior 

 antennae simple ; ovary single. 



Four species : one aquatic, three marine. 



C. minutus (PL 20. fig. 6). Thorax and 

 abdomen not distinctly separate, coiisisting 

 of ten segments, successively diminishing 

 in size, the last terminating in two short 

 lobes, from which issue two long filaments, 

 slightly serrate on their edges; antennae 

 short, seven-jointed in the male, nine in 

 the female ; inferior antennae simple, two- 

 jointed, the first joint with a small lateral 

 ■joint, terminated by four setae ; feet five 

 pairs. 



Common in ditches ; colour reddish, 

 length about 1-15". (PL 20. fig._ 6 : a, in- 

 ferior antenna; b, first pair of jaw-feet; 

 c, second pair.) 



C. crypt Oram, Brady. In a coal-mine. 



BiBL. Baird, Brit. Entom.; Brady, Qu. 

 M. Jn. 1860, p. 23. 



CAOUTCHOUC— A gum-resinous sub- 

 stance contained in the milky juices of many 

 plants, but most abundantly in those of the 

 families Euphorbiacere, Urticace.'u and Apo- 

 eynacea3, whence the India-rubber of com- 

 mence is obtained. The caoutchouc appears 

 in the form of minute globules suspended in 

 a watery fiuid containing a gummy sub- 

 stance; SO that the milky juice may be 



regarded as a kind of emulsion. See 

 Latex. 



CAPILLARIES.— The minute interme- 

 diate vessels which the blood traverses in 

 passing from the arteries to the veins. 



The capillaries appear to consist of a deli- 

 cate, transparent, tolerably resisting and 

 elastic membrane, and a number of oval or 

 rounded longitudinal nuclei ; but when 

 treated with very dilute solution of nitrate 

 of silver, the dark dyed outlines of the epi- 

 thelial cells, to which the nuclei belong, are 

 brought to light (PL 51. fig. 31). The dia- 

 meter of the human capiUaries varies from 

 1-5000 to 1-1000", the most common being 

 perhaps 1-3000". The size of the capillaries 

 in the Vertebrata generally, bears a relation 

 to the size of the coloured corpuscles of the 



Fig. 99. 



Magnified 300 diameters. 



One of the smallest vessels from the arterial side. 1, 

 smallest artery ; '2, transition ve-isel ; 3, large capillaries ; 

 4, small capillary, a, structureless membrane \yith few 

 nuclei, representing the adventitious coit; 6, nuclei of 

 the muscular flbre-cells; c, nucleus inside the small 

 artery; d. nuclei of the capillaries and intermediate 

 vessel. From the human brain. 



blood ; and thus they are largest in Birds, 

 Fishes, and Reptiles. The larger capillaries 



