l6 



NA TURE 



[November 3, 1898 



Messrs. Hershell and Lebour have shown, upon the amount of 

 moisture which the specimen holds. An accuracy of only one 

 per cent, is therefore claimed for the determinations. The 

 absolute conductivities of the marbles, calculated on the 

 assumption that the conductivity of the standard glass was 

 000277, are between 000501 and 000761. Special attention 

 is drawn to two groups of fine-grained marbles, which have 

 conductivities of about 00068 and 0-0076 respectively, at about 

 30' C. 



The principal facts referring to the origin of the metamor- 

 phosis of insects are summarised by Mr. J. W. Tutt in the 

 volume of Transactions just issued by the South-Eastem Union 

 of Scientific Societies (Taylor and Francis). Metamojrphosis, 

 he concludes, appears to be an adaptive habit which certain in- 

 sects have adopted, in their struggle for existence against those 

 enemies by which they are everywhere surrounded, and against 

 those animals that compete against them for food. The habit 

 of flying, by which they are able to escape from numberless 

 enemies that have not this power, was probably one of the first 

 factors in their development that led to their ultimate success. 

 The additional ability to store up food in the early active (larval) 

 stages of their existence so as to allow them to adopt a hiding 

 habit and quiescent external form at the most critical period of 

 life, must, however, have been the proximate cause of that 

 success which has culminated in their being numerically the most 

 successful types of terrestrial life in existence, the number of 

 species being almost incredible. 



Writini; with reference to the account of the resuscitation of 

 a toad taken from a snake, which appeared in Nature of 

 August II (p. 344), a correspondent in the Purneah district, 

 India, informs us that similar occurrences are common in parts 

 of India. He remarks: — " Almost any snake can be made to 

 disgorge what he has just eaten if worried a bit, and on number- 

 less occasions I have seen this done with grass snakes, and seen 

 a toad or frog, generally the latter, hop away rejoicing. . . . Snakes 

 when angry or alarmed apparently have the power of throwing 

 up their food, and only the other day I caught a 'dhamin,' a 

 harmless but ver)- savage snake — a small one, about 40 inches 

 long — and put him in a box with a glass lid. The next 

 morning I found two half-digested rats which the snake had 

 thrown up. The same thing happened once with a black cobra, 

 whose meal had also consisted of two rats with the addition of 

 a sparrow." 



A voi.l'ME of Transactions and Proceedings (vol. xxx. , 1897) 

 of the New Zealand Institute, edited and published under the 

 authority of the Board of Governors of the Institute by Sir James 

 Hector, K.C.M.G., F. R.S. , has been received. Several of the 

 papers in it have already been referred to ; and the limitations of 

 available space prevent us from referring to more of the present 

 volume than a presidential address by Mr. \V. T. L. Traverson 

 material and scientific progress in New Zealand during the 

 Victorian Era. Sir James Hector's work in New Zealand justly 

 entitles him to distinction among the explorers and discoverers 

 who have advanced the knowledge of the physical characteristics 

 of the globe during the past sixty years. He commenced his 

 duties as geologist to the Provincial Government of Olago in 

 1861, and under his direction very valuable investigations were 

 made. Mr. Travers points out, however, that geological work 

 in the field practically ceased in 1893, since which date Sir 

 James Hector has not been provided with the necessary staff for 

 pursuing it. Why this is the case is not clear, but the inter- 

 ruption in the work of one of the mo.st important scientific 

 dejxirtments of the Colony is much to be regretted. 



Kekerrino to the biological interests of the islands of New 

 Zealand, Mr. Travers remarks, in the address referred to, that 

 though the reptilian life found is very limited in extent, it con- 

 NO. I 5 14, VOL. 59] 



tains two forms of the most remarkable character — namely, the 

 Tuatara lizard and a frog known as Ijiopclma fiochstetteri, found 

 chiefly in the Coromandel district. The lizard is only now 

 found in some of the outlying islands, where its continued ex- 

 istence is threatened by the introduction of the pig and the cat. 

 The affinities and structure of this reptile have been the subject of 

 many memoirs, both by New Zealand and foreign naturalists, 

 who have shown that it is evidently connected wiih some of the 

 most ancient fossil forms. The frog is remarkable chiefly as 

 occurring in an oceanic island. It is satisfactory to know that 

 the fauna and flora of New Zealand have been, and are, studied 

 by many collectors and investigators, the results of whose work 

 have been embodied either in separate volumes or manuals pub- 

 lished by the Government under the editorship of Sir James 

 Hector, or in the shape of memoirs in the Transactions of 

 the New Zealand Institute, such as those in the volume lately 

 issued. 



The age of Niagara Falls, as indicated by the erosion at the 

 mouth of the gorge, was the subject of a paper by Prof. G. 

 Frederick Wright, read at the recent Boston meeting of the 

 American Association. The late Dr. James Hall early noted 

 the significant fact that " the outlet of the chasm Ijelow Niagara 

 Falls is scarcely wider than elsewhere along its course." This 

 is important evidence of the late date of its origin, and it has 

 been used in support of the short estimates which have been 

 made concerning the length of time separating us from the 

 Glacial period. A close examination made by Prof Wright 

 this summer greatly strengthens the force of the argument, since 

 he found that the disintegrating forces tending to enlarge the 

 outlet and give it a \'-shape are more rapid than has been sup- 

 posed. As the result of his investigations, he concludes that 

 a conservative estimate of the rate of disintegration for the 

 70 feet of Niagara shales supporting the Niagara limestone 

 would be one inch a year, with a probable rate of two inches a 

 year. But at the lowest estimate no more than 12,000 years 

 would be required for the enlargement of the upper part of the 

 mouth of the gorge 1000 feet on each side, which is very largely 

 in excess of the actual amount of enlargement. Some of the 

 recent estimates, therefore, which would make the gorge from 

 30,000 to 40,000 years old, are regarded as extravagant. Accord- 

 ing to Prof. Wright, the age of the gorge cannot be much more 

 than 10,000 years, and is probably considerably less. 



Dr. Ad. Struck, of Salonica, contributes an interesting 

 paper on the Macedonian Plain to the issue of Die Natur 

 for October 9. Some details of the mean temperature and 

 rainfall are given, and a short account of the chief products of 

 the region. 



The BolUttino of the Italian Geographical Society for 

 October contains a paper, by M. Baratta, on the geographical 

 distribution of earthquakes in Umbria. .\ll the authentic 

 records in existence are summarised and discussed, and a ma{> 

 showing the chief regions of seismic disturbance is appended. 



We have received a copy of the double number of SptluncOy 

 the organ of the French Social/ de Spileologie, for the first half 

 of the current year. This journal is now in the fourth year of 

 its existence, and it continues to publish valuable papers on 

 subjects connected with caves and other subterranean structures. 

 The present number contains some notes of interest on the pro- 

 tection of sources of potable water, indicative of increased 

 attention to this matter in France. 



A I'Ai'ER, by Prof. Dr. J.Walther, on historical and geological 

 aspects of the problem of the course of the Oxus, appears in 

 Petermann's Milthtilun^en. Dr. Walther shows that the Oxos 

 has always flowed into the .Sea of Aral, and that the belief 

 that its waters reached the Caspian arose from ignorarv^c of the 



