OF THE AMAZON VALLEY. 505 



Ithoiilio of tlic locality bciiiii' thus clKm^-cd, how stands it with the Lc}j/«i/i(k's? Tht'v 

 are chaiiLjed also, and ai^'aiu with close rclcrcnce to the Jthoinid'. i found a number of 

 different varieties, wliich I could not doubt were local forms of the same species as that 

 found on the Cupari and at Ega. Thus, there was one" (I'l. LV. lig. 2) closely resemltling 

 L. T/ieoiioe {tiii. 1), but moditied to produce a nearer imitation of the Itltoitiia Onega 

 (PL LV. fii?. 2r/), which 1 believe to be a localform of /. i•7o/v^ Another (PI. LVI. fiif. 3) 

 resembled UhoiuUi (JhrijHodoii'ni (PL LVI. lii^. 3<r) ; but the imitation is iu)t fixed or exact 

 in all the sjx'cinu'ns taken, as may be seen by com])arini^' lii^s. 1, 2, 3, of the same; Plate. 

 We here detect natnre, as it were, strlrhig after a correct imitation : tlu' explanation of 

 this will be attempted further on. A third form of Lcjddlis found at St. Paulo is the 

 one fit^'ured PL LVI. liy-. (i, which mimics the TUiomia I'iru'ntui (PL LVL fii,'. (J«). 

 Besides these, a i\'\\ varieties occurred which did not closely counterfeit any llhomia ; 

 they were very much rarer than the others. I tigure two of these (PL LA', liiis. 7, 9), to 

 show how they connect the othei- more strongly modilied varieties witii the Ega forms. 



The Ithoiiihc concerned in these imitations luivc the character of true species, being 

 distinct and constant, with the exception of /. C/wf/sodoi/ic, whose varieties are detailed 

 under the head of the species, which is variable, and tiii'ows light on the origin of the 

 rest. They are all excessively numerous in indiWduals, swarms of eacii kind being found 

 in the localities they inhabit. The Lcjjlclidrs are exceedingly rare; they cannot be 

 more than as 1 to 1000 with I'cgard to the Jlhoni'ia'. it may be asked, how can we know 

 they are all \aricties (using the tei'ni as meaning forms descended iVom others) of one 

 sjK'cies ? 1 must refer to the figures gi\-en, which, although they do not incliule all the 

 connecting varieties that wen; collected, show^ how lu-arly all the forms are linked to- 

 gether. The most distinct amongst them are those figured I'L L\'l. tiiis. !• and (i. The 

 feature which (list im;'uishes fig. \ is the white colour of the disk of the hind winii's. and 

 the veins which traverse it. This character is shown to be due to variation, from the 

 facts that Jthoinia OiiridiK, an undoubtc-d variety of /. i'hrijmdonla (or Orolitia), exhibits 

 a commencement of this milky shade of the wings, and that many individuals of /. flcr- 

 (llud (I'L L\'I. W'x. \(t) (lis|)lay steps of modiiieat ion in the colours of the veins. The 

 variety iigui'ed I'L L\'I. 111;'. (!, ap|)ears distinct, from the singl(> pale spot near the tips of 

 the wings; an apjjroximation to this is seen in the variety figured PL L\'. iig. '.), wliich 

 is an undoubted modification of L. Lii.s'n/oi' (PL L\'. fig. .'5). The remarkable variety 

 figured PL L\'. Iig. !■ has been described by the only author who has treated on these 

 insects (Mr. llewitson) as a variety of L. Lf/s/t/oe. In a polymorphic form, like this 

 L('pt((lifi, none of the varieties can be taken from the rest ami denominated species, 

 (using the term as meaniiu;' foi-ms which cannot have descended from other closely allied 

 ones), without exercising the art of species-making in the most arbitrary manner. Loi' if 

 we allow so gr(>at a latitude to variation as that from ligs. ,'{ to 1, .">, (i, 7, S, and \), PI. L\ .. 

 how can we vent ure to say that nat ural modification, having gone so far. was incompetent 

 to go further, so as to ])roduce ligs. I and O, i'l. L\'l., and that those forms must have 

 arisen by .some unknown agency? It is true, they ha\(- not arisen I)y simple variation, 

 or sporla, in one generation, but, as we shall ])resently see, by an I'xternal agency 

 accumulating the nu)diiications of many generations in two diverging directions. As 



3 v 2 



