SC/HNCE-GOSS/P. 



35 



in calm wciUlicr, iif a huge mirror in a rocky frame- 

 worii of tnj;ir(llint; cliffs. 



The lakelet is such only in name. On the nDrthorn 

 side its waters are connected with the Mediterranean 

 hy a long tunnel. This, the waves, raised by the 

 Mneslrale, have ploughed through the massive coast 

 cliff, and, through it, in the winter time, the storm 

 waves surge in impotent fuiy, converting the hollow 

 into a cauldron of lH>iling, seething foam. 



.'\way to the south of Dueira lies a typical Go/.ilan 

 hamlet, with its (|uaintlygabled houses, and its 

 clusters of I'hoenicinn rock tombs. Many of the 

 tombs have been destroyed by the peasantrj-, but 

 sufficient of them remain to show that Ghar Gherduf) 

 and San Giorgio were not the least important of the 



numerous I'hiwnician burying places that lie ficattered 

 over the Islands. 



Kighl and left of these old-world selllcments, ihc 

 view of the Mediterranean is r)bstructed by mural 

 crags of grey limestone, that tower to a height of 400 

 feet above the waters of the little bay of Dueira. 

 These cliffs rise, regular but abrupt, their crests 

 broken, |)erforated and rendered fantastic.illy rugge<l, 

 with a profuse giowth of spurge and trailing clusters 

 of the l-eguminosae. 



Of sights, such as one would expect to find in the 

 more popular resorts of Europe, Gozo is poor indeed ; 

 but in tradition, historical association, and undefilcd 

 nature, the Myperia of the poets is without an etjual. 



Kavcnswood Road, Rcdland, Bristol. 



lU'TTEKI'l-ll'-S OI- Till'. l'.\I..\K.\k(TIC Rl'.GIOX, 



By 1|K\KV CiiAKi.Ks L\m:, M.Ii., M.K.C.S.. 1..K.C.P. LoM). 

 {Continued from />agc $}, 



\".\KIA'l'ION. 

 T^-IIK subject of variation is one of great import- 

 ■^ ance. We have to draw a line between 

 accidental varieties and local varieties, or races. 

 The first are designated by the term aberration {at>), 

 and signify those varietal forms which are found in the 

 same localities, at the same season, and conjointly 

 with the ordinary form. Some of these aberrations 

 are produced constantly ; such as Thais mcdcsicastc, 

 ab. hoiioralii B. , Colias cdiisa ab. lie Hi e lib., 

 Arf^'iniis adippe ab. ckodoxa O. Other aberrations 

 occur sporadically as individual forms, anil some are 

 either very rare or else almost unique, as for instance 

 Vanessa polythloros ^. tesludoVi%^., V. aiitiopa ab. 

 hygiaea H. True varieties or local races are those 

 forms which more or less replace the typical form of 

 the species in particular localities, t.,;'. , Papilio 

 podal iritis var. feist liaiiielii, Anlhochai is tagis var. 

 bcllezina, Melitaea aurinia vars. merope and pro- 

 viiieialis, Lyeaena eros, var. eroidcs, J,, astrnrehc var. 

 artaxerxes. 



It must, however, be borne in mind that variety 

 and aberration are not constant zoological terms ; 

 what is in one place a true variety, may occur else- 

 where .IS an aberration. For e.xample, the form of 

 Apatitra ilia called clytie is sometimes a variet) , and 

 in some places may occur with the type, as an aber- 

 ration. Some forms that are at present accepted as 

 varieties, are, perhaps, distinct species, or in process 

 of becoming such in time. For these Dr. .Staudinger 

 has employed the term '' Darwinian species," after our 

 great exponent of the law of evolution. I shall 

 enumerate several of these as distinct species, 

 especially in such genera as J'aniassiits, Colias and 

 Melitaea. In many alpine varieties there is probably 

 a leversion to a primitive boreal type, such as in 

 .1/. aurinia var. iiienpe, /'ieris iiapi var. hryoiiiac, etc. 



SkASONAI. UlMOKl'lllSM. 

 Hy seasonal dimorphism is meant that in species 

 which undergo their transformation more than once 

 in the year, there is fre(|uently a marked difference in 

 the appearance of the broods. This condition is 

 much more universal than was formerly supposed. 

 In tropical species wet and dry season forms are often 

 strongly difterentiated ; and in the Palaearctic species 

 the spring ,ind summer broods frequenily exhibit con- 

 stant difference. These seasonal forms are usually 

 treated as varieties by modern entomologists. They 

 are the result of differences in climatic influences. We 

 see in some of our common British species, such as 

 Pieris iiapi, examples of this divergence. In many 

 Continental species it is very marked, especially in 

 the case of Vanessa levaiia L., where the spring 

 brood differs entirely from that of the summer, 

 insomuch that Linnaeus gave them two distinct 

 specific names. The latter is a black butterfly, wirh 

 while bands; the former fulvous brown, with bLick 

 markings. 



SKxt'Ai. Dimorphism. 



In some species the female exhibits several forms 

 diftering in coloration and .sometimes in pattern ; 

 these forms are treated as aberrations. Examples 

 may be .seen in the female aberrations of Thais 

 deyrollei and Theela faseiata, where several forms are 

 found. The ab. hetice of Colias ediisa is a very well 

 know n example, which is followed by many species 

 of the genus, such as C. aurora, C. myrmidone, C. 

 erate, etc. This tendency in the genus Colias, towards 

 a whitish ground colour, replacing the usual yellow 

 or orange in the female, Ls very probably due to a 

 reversion to a primitive coloration. It is a remarkable 

 fact that in some species of the genus, the females are 

 always of a light colour, whilst the males are yellow 

 or orange. 



C 2 



