CYANOSIS 



CYCADS 



635 



Cyano'KlM (Gr. kyanoa, 'blue'), lividity of com- 

 plexion, wiili I'M I liit-- -it tlie capillaries and minute 

 \fins, especially of the face and lips. A name 

 cli;iiii<-tensticiilly applied to the colour in certain 

 eases of oonoenita] disease or malformation of the 



heart. See HEART. 



Cyanotyue is a photograph obtained by the 

 use of a cyanide. See PHOTOGRAPHY. 

 Cyathra* See TREE-FERN. 

 Cybele (calle<l also Affdistis and Dindymene), 

 an ancient goddess whose worship was universal in 

 I'lirvgia, ami widely spread in Western Asia as 

 that of ' the great mother ' or ' the mother of the 

 gods." She seems to have l>een a nature divinity, 

 whose worship was attended with wild orgiastic 

 rites, many of which were adopted by the Greeks 

 from the eastern nations. The Greeks, moreover, 

 identified the oriental Cybele with their ancient 

 earth goddess Klieii, whose worship seems to have 

 originated in Crete, where she is associated with 

 the Curetes. Among the Romans she was con- 

 sidered as identical with Ops, the wife of Saturn, 

 and mother of Jupiter. In Phrygia her priests 

 were the Corybantes, who worshipped her noisily 

 witli drums, cvmbals, and horns, dressed in full 

 armour. The Roman priests of Cybele were often 

 called Galli. In art Cybele is usually represented 

 seated on a throne, adorned with a mural crown, 

 with lions crouching to the right and left, or sitting 

 in a car drawn by lions. See RHEA. 



Cycads, or CYCADACE^E, an order allied to 

 Comferce. (see GYMNOSPERMS), but in vegetative 

 appearance rather resembling ferns and palms. 

 The stem, which is externally covered with leaf- 

 scars, may be so short that the crown of leaves 

 arises little above the surface of the ground ; more 

 frequently, however, it rises to a height of a few 

 feet, then resembling a tree-fern ; and in excep- 

 tional cases (e.g. Cycas media of Australia) may 



attain a height 

 of 50 or 60 feet. 

 The foliage- 

 leaves, which 

 develop under 

 the protection 

 of reduced bud- 

 leaves, are usu- 

 ally pinnate, 

 and mostly 

 parallel-veined; 

 but in Cycas we 

 have a middle 

 vein only, and 

 in the curiously 

 fern-like Stan- 

 geriaamid-vein 

 with lateral 

 branches. The 

 leaves are 

 always of more 

 or less leathery 

 consistence, and 

 sometimes be- 

 come very hard 

 and spiny at the 

 tins and on the 

 edge. In Cycas 

 the pinniw are circinate in bud as in ferns, although 

 the midrib is straight ; conversely in Zamia, the 

 leaf itself is inrolled, although the pinnae are 

 straight ; in others, however, where both are 

 straight, the pinme overlap each other from above 

 downwards, as in the moon-wort fern (Botry- 

 chium). The stem is of complex internal struc- 

 ture, but is thickened by permanent cambium. 

 It may bear lateral buds on the axils of old leaves, 

 especially in unhealthy plants ; and these may fall 



Fig. 1. 

 A, Cycas Norinanbyaua ; 6, c, Cycas media. 



off and propagate the plant. In wmie caw*, how- 

 ever, we have an apparent dichotomy, although 

 jimlialily due to branching. Dichotomy of tin: 

 routs has also been described ; this, however, not 

 as a normal development, but due simply to irrita- 

 tion by a fungus- mycelium or a noxtoc-like alga, 

 which commonly invests the root, and even pene- 

 trates the tissue (see SYMBIOSIS). Yet among 

 those who admit the pathological nature of thU, 

 some still regard it as an atavistic reap|>earance, 

 the last surviving trace of the dichotomy so com- 

 mon among the ancestral cryptogams (see FERNS, 

 LYCOPODIACE^E ). 



The exceedingly primitive flowers are found on 

 separate plants, and are respectively composed 

 simply of staminate or pistillate leaves, in loth 

 cases usually spirally aggregated as cones. The 

 stamens are reduced and undivided leaves bearing 

 on their dorsal surfaces a usually indefinite number 

 of pollen-sacs, so furnishing a perfectly inter- 

 mediate form between the sporangium-bearing 

 frond of a fern and the stamens of higher plante. 

 The pollen -grains show a very distinct remnant o 

 the male prothallium. 



Passing to the female flowers, we find those at 

 least of Cycas to be terminal on the axis, which 



Fig. 2. 



o, Stamen of Cycas circinalis, under surface ; 6, group of pollen- 

 sacs (Microsjiorangia); d, pollen-grain of Ceratozamia ; c, the 

 same germinating ; e, carpellary leaf of Cycat revoluta, with 

 lower pinna; reduced and bearing ovules ; /, stamen of Zamia 

 integr\folia. 



after flowering resumes vegetative growth, a con- 

 dition which occurs only as an anomaly or rever- 

 sion in higher plants (e.g. proliferous roses). The 

 separate carpellary leaves retain more or less 

 distinct traces of vegetative character ; thus in 

 Cycas the ovules ( microsporangia ) represent the 

 reduced lower pinna' ; more frequently, however, 

 only two are developed (Zamia, fig. 2); but the 

 carpellary leaf is always open, and shows no trace 

 of that still more precocious development of its 

 ovules and arrest or its opening altogether, which 

 would give us the ovary of the higher flowering- 

 plants (see OVARY). On ripening, the cone may 

 fall to pieces, liberating the ovules ; in the simpler 

 Cycas the separate naked seeds become modified and 

 enlarged into large fruit-like bodies, with an outer 

 fleshy and an inner stony wall. The nucellus is 

 crushed into little space by the growth of the endo- 

 sperm, which contains the straight embryo with 

 its one (Ceratozamia) or two, often unequal 

 (Cvcas, Zamia), cotyledons. 



The more vegetative character, both of the flower- 

 ing axis and of the carpellary leaves, which dis- 

 tinguish Cycas from all the other genera, explains the 

 separation of the order by systematise into Cycaden? 

 and Zamia>. Amonfj tlie latter, Stangeria of Port 

 Natal is at once distinguished by its pinnate vena- 

 tion ; and Bowenia of Queensland by its bipinnate 



