Sept. 1 8, 1879] 



NATURE 



481 



fi^rmed lizards, I shall just mention a third endeavour which has 

 been made to explain the black colour of the lizards inhabiting 

 small islets. 



In his interesting book, " Beitriige zur DescendeDz-Theorie, " 

 Leipzig, 1876, Seidlitz has tried to introduce the belief that the 

 black colour serves as an armour or protection to the animal 

 against the bitrning rays of the sun. Thereupon I sought to 

 prove that reptiles inhabiting the desert would need such a pro- 

 tection more than the others, yet they are not black. 



As some might perhaps draw, from what I have said, the 

 conclusion that, according to my hypothesis the reptiles of the 

 desert should be also black, I must remark that the scorching 

 rays of the sun in the desert effect so strong pn elevation in the 

 temperature of the soil, that it brings forth a relaxation in the 

 animal, and slackens the energetic movement of the pigment, 

 consequently the extreme heat counteracts the effect which the 

 light produces, whilst on the islets of the Mediterranean the heat 

 is alleviated by the sea breezes and by a certain degree of damp- 

 ness. As we already know, all our European species of lizards 

 carefully avoid the desert. 



The dark-coloured lizards at present known, which inhabit 

 small islands, are the following ones : — 



1. Lacerta muralis, -'ar. archipdagica, De Bedriaga: "Die 

 Faraglioni-Eidechse." (Heidelberg, 1876; pp. 19.) L. muralis, 

 var. B. Erhard : "Fauna der CyUaden," (Leipzig, 1858; pp. 

 80.) L. muralis, var. C, Schreiber: " Herpetologia europjea." 

 (Braunschweig, 1875 ; pp.408.) L. muralis, var. archipelagica, 

 V. Bedriaga : " Herpetologische Studien," im Archiv fiir Nalur- 

 geschichte, 1878. 



Back and extremities black, covered with rows of green spots. 

 Belly and tail black. Inhabits the Cyclades. 



2. Lac. muralis var. inelisellensis, Braun ; Lacerta lilfordi 

 and L. muralis ; " Arbeiten aus dem zoolog. zootom. Institut in 

 Wiirzburg, 1877." 



Back brown, ornamented with six light longitudinal stripes. 

 Belly dark blue, chin rather lighter. Length 130 mm. Inh.ibits 

 the islet Melisello near the island of Lissa, in the Adriatic Sea. 



3. L. muralis, var.jiljlaensis, De Bedriaga : "Die Faraglioni 

 Eidechse." (Heidelberg, 1876.) Braun, I.e. v. Bedriaga: 

 " Herpetologische Studien," in Archiv f. Naturg., 1879. 



Giinther : " Description of a new European Species of Zootoca," 

 Annals and Magazine of Natural History, 1874. 



Back black covered with small green specks, the under parts 

 are deep blue. Length 212 mm. Inhabits Filfla, near Malta. 



4. L. muralis, var.faraglionicnsis, De Bedriaga : " Ueber die 

 Entstehung der Farben bei den ludechsen." (Jena, 1874.) 

 L. muralis var. carulaa, Eimer : " Zoologische Studien auf 

 Capri." (Leipzig, 1874.) Braun, I.e. 



Back black, the sides blue spotted with black ; the belly a 

 brilliant blue. Length 220 mm. Inhabits the Faraglioni Rock, 

 near Capri. 



5. L. muralis, var. Latastei, De Bedriaga: "Herpetologische 

 Studien," in Archiv f. Naturg., 1S79, pp. 264. 



Itack and sides brown, or dark brown covered with black 

 spots, sometimes with bluish green spots on the sides. Above 

 the root of the forelegs a bluish spot. Length 205 mm. In- 

 habits Ponza near Gaeta. 



6. Z, muralis, var. Lilfordi, Giinther: " Description of a New 

 European Species of Zootoca," I.e. Braun, I.e. 



Upper parts of a deep glossy black, lower parts of a beautiful 

 sapphire blue. Length 175 mm. Inhabits the Island of Ayre, 

 near Minorca. 



7. L. muralis, var. Gi^liolii, De Bedriaga : "Herpetologische 

 Studien," 1879, I.e. 



Forepart of the back covered with alternately green and blue 

 stripes. The hind part of the back is dark blue. The sides 

 are light brown with green and blue spots. The belly brick-red 

 with (sometimes without) small blue stripes. Colouring varies. 

 Length 175 mm. Inhabits Isla del Dragoneras near Majorca. 



8. L. muralis, var. Rasquineti, De Bedriaga : " Herpeto- 

 logische Studien," 1878, I.e. 



Back olive brown with a black pattern. Blue eye-spots orna- 

 ment the sides. Belly brick-red. The first longitudinal rows of 

 I the ventral scales are blue. Length 185 mm. Inhabits the islet 

 ! La Deva near Arnao (Spain). J. voN Bedriaga 



Heidelberg, August 28 



Insect Swarms 

 This year being remarkable for " insect swarms," it is im- 

 portant that all possible information about them should be gained, 



so as to satisfactorily account for these phenomena. As to 

 Vanessa eardui, which has been abundant throughout the spring 

 and summer, it is possible that some of those specimens which 

 occurred in the spring were the result of a migration from the 

 Continent, but there is no doubt that the specimens which are 

 now seen are nearly, if not all, bred in this country from ova de- 

 posited by the spring specimens, quite sufficient time having 

 elapsed for the metamorphosis. With regard to Plusia gamma, 

 I am of opinion that all the specimens seen, and they have been 

 in profusion here from about August 10 till the present time, 

 have been bred in this country. My reason for so believing is 

 that the larvre were most abundant in the spring, doing damage 

 in gardens to a great extent. Some of these larva; I fed np, the 

 perfect insects emerging at the time P. gamma first appeared in 

 abundance. My experience of the swarms of P. gamma is that 

 they moved in no particular direction, merely passing in numbers 

 from flower to flower, flowers being scarce this year, any 

 apparent migration being simply a search for more flowers. In- 

 stead of putting the cause of these swarms down to "migra- 

 tion," endeavours should be made to discover the causes of the 

 extraordinary periodical fecundity. It is quite probable, too, 

 that next year, P. gamma and V. eardui will be scarce, as is 

 frequently the case with Colias edusa and hyale after a year of 

 abundance. J. H. A. Jenner 



Lewes, September 13 



Earthquakes 



I HAVE observed, in several recent numbers of Nature, 

 various notices of earthquakes, so frequent as to suggest the 

 idea to me (perhaps incorrect) that for several months past they 

 have been more numerous than u :al. Since my arrival in West 

 Java I have experienced several severe shocks. On March 28, be- 

 tween 7 and 8 p.m., I was startled by a peculiar shivering as I sat in 

 my chair. At first I imagined I was seized with a terrible fever- 

 less ague, but I was soon undeceived by the increased bumping and 

 the clashing of my bottles, &c., and the vehement beseeching of 

 Tuhan Allah, and the loud exclamations of the natives of, " We 

 are here !" "We are all here!" I learned in a few days that 

 several villages lying at the base of the peccant volcano, Gede, 

 had suffered ; in particular the town of Ijandjoer, in which 

 numerous houses \\ ere destroyed, many bridges broken dow n, 

 the telegraph apparatus entirely thrown out of gear, and six or 

 seven persons killed. The ground also opened and emitted 

 volumes of smoke, while the Cede itself burst out with extra 

 vigour, throwing out, in addition to the usual white steamy vapour, 

 large quantities of smoke and ashes, fortunately to no great 

 distance. Throughout the 28th and 29th there was a succession 

 of shocks. On June 3 I experienced a second earthquake, un- 

 dulatory but not very severe ; and again on the 5th, undulatory, 

 of considerable duration, and severe enough to thoroughly shal;e 

 the whole house and throw down unfixed objects. These have 

 done no damage to life, as far as I have heard, and, beyond 

 some houses being cracked in Batavia, little to property. Since 

 the beginning of March there have been numerous shocks, but 

 none so violent as those of March 28 and June 5. Immediately 

 preceding the shock of June 5 there was a sudden and heavy 

 fall of rain, the drops being very large. The direction of the 

 wave was from east to west. Henry O. Forbes 



Kosala, Bantam, July 



Leaping Power of Mantis^ 



I CAN state from my own observations of several different 

 species, both in Ceylon, South Africa, and Fiji, that the power 

 is possessed by many, chiefly in the larval stage, and that the 

 distances they can spring from branch to branch are very consi- 

 derable for the size of the insect. E. L. Layard 



British Consulate, Noumea 



OUR ASTRONOMICAL COLUMN 

 The Outer Satellite of Mars.— The following 

 positions of Deimos, the exterior satellite of Mars, are 

 deduced from the data published in Prof. Asaph Hall's 

 memoir, in which he determines the elements of the 

 satellite-orbits : — 



* Nature, vol. xx. p. 595. 



