Occasionally Venus is called Cytherea, from the island near which Greek myth represented her as having arisen from the sea. Thus in the _Knightes Tale_: "He roos, to wenden on his pilgrimage Un-to the blisful Citherea benigne, I mene Venus, honurable and digne."[120] and in the _Parlement of Foules_; "Citherea! thou blisful lady swete,"[121] The relative positions of the different planets in the heavens is suggested by allusions to the different sizes of their spheres and to their different velocities. In the _Compleynt of Mars_ the comparative sizes and velocities of the spheres of Mercury, Venus and Mars are made the basis for most of the action of the poem. The greater the sphere or orbit of a planet, the slower is its apparent motion. Thus Mars in his large sphere moves about half as fast as Venus and in the poem it is planned that when Mars reaches the next palace[122] of Venus, he shall by virtue of his slower motion, wait for her to overtake him: "That Mars shal entre, as faste as he may glyde, Into hir nexte paleys, to abyde, Walking his cours til she had him a-take, And he preyde hir to haste hir for his sake."[123] Venus in compassion for his solitude hastens to overtake her knight: "She hath so gret compassion of hir knight, That dwelleth in solitude til she come; . . . . . . . . . Wherefore she spedde hir as faste in her weye, Almost in oon day, as he dide in tweye."[124] When Phebus comes into the palace with his fiery torch, Mars will not flee and cannot hide, so he girds himself with sword and armour and bids Venus flee. Phebus, who in Chaucer's time was regarded as the fourth planet, can overtake Mars but not Venus because his sphere is between theirs and his motion is consequently slower than that of Venus but faster than that of Mars: "Flee wolde he not, ne mighte him-selven hyde. He throweth on his helm of huge wighte, And girt him with his swerde; and in his honde His mighty spere, as he was wont to fighte, He shaketh so that almost it to-wonde; Ful hevy he was to walken over londe; He may not holde with Venus companye, But bad hir fleen, lest Phebus hir espye. "O woful Mars! alas! what mayst thou seyn, That in the paleys of thy disturbaunce Art left behinde, in peril to be sleyn? . . . . . . . . That thou nere swift, wel mayst thou wepe and cryen."[125] In spite of his sorrow, Mars patiently continues to follow Venus, lamenting as he goes that his sphere is so large: "He passeth but oo steyre in dayes two, But ner the les, for al his hevy armure, He foloweth hir that is his lyves cure;[126] . . . . . . . After he walketh softely a pas, Compleyning, that hit pite was to here. He seyde, 'O lady bright, Venus! alas! That ever so wyde a compass is my spere! Alas! whan shal I mete yow, herte dere,'" etc.[127]