HARDWICKE'S SCIENCE-GOSSIP. 



187 



submarine eruptions, whose la)-ers have been laid 

 out under water and since elevated, with or without 

 a covering of limestone. (3) The remaining islands 

 are formed entirely of limestone. Eua is an example 

 of the second group. The volcanic basis consists for 

 the most part of beds laid out beneath the sea, and 

 some of the upper ones contain pelagic shells. Dykes 

 of augite and hyperthene-andesite project on the 

 shore, and a representative of the plutonic series 

 occurs. There is evidence that the island has been 

 elevated and again submerged prior to the elevation 

 which has raised it to the present height. The 

 volcanic basis is largely invested with limestone, and 

 this rock forms the summit 1078 feet above sea-level. 

 Sections show that it is a shallow-water deposit. Of 

 the purely limestone structures, Tongatabu, Nomuka, 

 and the long reef on which the larger islands of the 

 Hapaii group are situated form more or less complete 

 atolls, all of which have been elevated to a greater or 

 less extent. The Vavau group is remarkable for its 

 very indented contour, suggesting the idea that it 

 rests on a much denuded basis. Both here and at 

 Eua there are raised limestone formations with atoll 

 or barrier-like contours ; and there is some direct 

 evidence to show that these have been formed 

 without the aid of subsidence. The presence of 

 islands formed of volcanic materials laid out in layers 

 beneath the sea, and the manner in which the 

 recently formed Falcon Island is now being reduced 

 to the condition of a submarine bank, suggest that 

 the atolls of the group may rest on similarly formed 

 foundations. In the discussion which followed, Mr. 

 Hickson said that Mr. Lister's researches on the 

 coral reefs of the Friendly Islands were of great 

 interest and importance, as they supported the view 

 that atolls and barriers may be formed in regions of 

 elevation, and that the "subsidence theory" is not 

 sufficient to account for all the phenomena that occur 

 in volcanic regions. The Tonga and Kermadec 

 groups of islands are very similar to the chain of 

 islands that stretches from the Northern Peninsula of 

 Celebes to the southern promontory of Mindanao. 

 Here we find a chain of volcanoes, many of them 

 active at the present day, represented by the Ruang, 

 the Siauw, and the Awu, with broad barrier-reefs 

 and ring-shaped atolls in their immediate vicinity. 

 The researches of Sluiter in the Java seas prove that 

 coral islands and reefs are frequently formed on a 

 substratum of soft clay and mud. Mr. J. W. Gregory 

 remarked on the great value of Mr. Lister's paper, 

 and the interest attaching to the discovery of a 

 plutonic rock on the islands. Taken in conjunction 

 with the discovery of similar rocks in the Marquesas, 

 and the presence there of genera otherwise restricted 

 to South America and Malaysia, it helped to afford 

 an explanation of some difficult problems of distri- 

 bution. Manganese nodules seem characteristic of 

 deep-sea conditions, not only at present, but in 

 earlier periods; thus in the Maltese Miocenes they 



are associated with a fauna of about looo fathoms. 

 Their occurrence, therefore, proves considerable ele- 

 vation, and it is not surprising that the coral-lime- 

 stone occurs as thin crusts ; the Tongas thus afford 

 only another case of coral formation in shallow or 

 rising areas, for which, as Darwin has so emphatically 

 insisted, his theory was not proposed. 



The Inverness Earthquakes of November 

 15TH TO December 14TU, 1890. By Mr. C. 

 DaviSon, — In this paper the author gives reasons for 

 supposing that the Inverness earthquakes of last year 

 were due to the subsidence of a great wedge of rock 

 included between a main fault and a branch one ; 

 and he considers that there is little doubt that these 

 recent earthquakes were the transitory records of 

 changes that, by almost indefinite repetition in long 

 past times, have resulted in the great Highland 

 faults. 



NOTES AND QUERIES. 



Bats Flying in Sunlight. — In the early summer 

 of the year before last, upon coming out of the 

 church here at the end of the morning service, I 

 observed two bats flying about in bright sunshine in 

 the churchyard, resting now and then on the tiled 

 roof of the south porch. It was the brightest, 

 hottest day there had been that year up to that date, 

 and I conjectured that their behaviour was due to the 

 circumstance that their roosting-place under the tiles 

 had become too hot for them. — Johfi Hawell, ALA., 

 Iiigleby Grcenhow Vicarage, Northallerton, Yorks. 



Snakes and Parasites. — Are snakes troubled 

 with parasites ? I have never seen any mention of 

 such being the case. For a considerable time I have 

 kept several of the common Tropidonotus natrix, and 

 until this week none of them have cast their skins 

 this year. I took a skin out of the cage two days 

 ago, which had just been cast, and was still fresh and 

 moist. On looking at it, I found several lice of some 

 sort crawling over the skin, but I brushed them off 

 at once without thinking, as I wanted to preserve the 

 skin. Last evening I found, in the space of about an 

 hour, another f»esh skin, which was also covered 

 with the lice. I send this skin by Parcel Post just as 

 I found it, that you may see the apparent parasites. 

 I should be glad to know what you think they are. 

 Is there any evidence as to snakes' hearing power? 

 It always seems to me that they feel the vibration of 

 a movement, more than actually hearing the noise of 

 it. I might say that in other years I have never 

 found any sort of insect on a snake's slough. — H. D. 

 Tilly. 



Marine Phosphorescence, etc. — During the 

 first week of June was seen, off the south coast of 

 Devon, one of the most beautiful natural phenomena 

 it has ever been my privilege to witness. Across 

 Torbay, beyond Hope's Nose to Babbicombe Bay, 

 on to Oddicombe and Petit Tor, far as the eye could 

 reach, the sea was dyed with brilliant crimson, which 

 in the bright summer sunshine looked as if the water 

 was turned into arterial blood, reflecting the light 

 with a weird and wonderful effect. But it was at 

 night the strange phenomenon revealed its full splen- 



