Dec. 7, 1888.] 



SCIENTIFIC NEWS. 



585 



almost impossible. Mr. Thomson then described a short 

 stay.they had at the city of Marakish, and went on to speak 

 of the ascent of the Tizi Likumpt at a height of 12,500 ft. 

 Here, rather to their surprise, they found a branch of the 

 Mrika river, penetrating into and running parallel to the 

 central axis. On the 9th of September they started on a 

 hazardous trip up the valley of the Imintanut, which was 

 a very narrow gorge, caused by the occurrence of an 

 almost vertical bed of compact limestone. They then 

 passed into another glen, that of the Wady Msira; crossing 

 that depression, they rose rapidly for half an hour, and 

 at an elevation ot only 4,500 ft. they found themselves at 

 the top of the pass that led into a tributary ot the Sous. 

 The impression that was acquired at the end of that pass 

 or watershed was that they were skirting the end of the 

 Atlas as a range, and that westward lay only a broad 

 plateau, cut off geologically and topographically from the 

 range to the east. They then travelled through Bibawan 

 to Tarudant, and traced out the tail of the Atlas range, and 

 remarked the manner in which the cretaceous sandstones 

 were thrown on the flank of the range, though com- 

 paratively undisturbed away from the immediate line of 

 upheaval. The lecturer then said that, after returning to 

 Casablanca, a despatch asking him to go to the relief of 

 Emin Pasha brought him home, or he had intended to do 

 a little more exploring. In conclusion, Mr. Thomson gave 

 some of the practical results of his trip. They had ascended 

 and crossed the Atlas chain in no fewer than six different 

 places besides making various subsidiary trips into the 

 lower ranges. A large series of barometric and boiling- 

 point observations had been taken which would assist in 

 forming a more accurate idea of the general elevation of 

 the range. Several glens had been explored and the head- 

 waters of some important streams had been mapped out. 

 New and important light had been thrown upon the geo- 

 logical structure of the mountains. A small collection of 

 plants from the higher altitudes had been made, and finally 

 a series of photographs (which were exhibited) of the 

 mountains, the inhabitants, and their houses had been 

 obtained. He had reached an altitude in the mountains 

 1,300 ft. or 1,500 ft. higher than any other traveller. 



ROYAL STATISTICAL SOCIETY. 

 The first ordinary meeting of the present session was 

 held at the Royal School of Mines, in Jermyn Street, on 

 the 20th ult. The President, Dr. T. Graham Balfour, 

 F.R.S., Honorary Physician to her Majesty the Queen, 

 occupied the chair. 



Before delivering his inaugural address, the President 

 congratulated the Society upon its continued prosperity 

 and numerical strength, and referred in terms of regret 

 to the losses the Society had sustained by deaths since 

 the anniversary meeting in June last, especially men- 

 tioning the services rendered to the Society in the past 

 by Mr. Frederick Purdy and the Rev. E. Wyat-Edgell. 

 He also urged on the Fellows generally, and the younger 

 ones especially, the importance of forwarding the objects 

 of the Society. 



The President then proceeded to show how errors 

 may arise in the use of figures under certain conditions, 

 and some of the benefits to be derived from statistics 

 when correctly and carefully employed. In illustration, 

 reference was made to the assumption that town life 

 leads to physical degeneration, as argued in an article on 

 the " Health and Physique of our City Populations," in 

 the Nineteenth Century of July, 1881, recently reprinted 



in "Prosperity and Pauperism," edited by the Earl oi 

 Meath. Other subjects and instances were also men- 

 tioned, showing how easy it is to arrive at erroneous 

 conclusions from a comparison of two periods without 

 regard to the important principle of similarity of the 

 conditions. 



Dundee Naturalists' Society. — At the meeting on 

 November 21st a paper on " The Origin of Coral Reefs" 

 was read by Mr. Alexander P. Stevenson. After drawing 

 attention to a large collection of corals from the Biological 

 Museum of the College which had been kindly lent by 

 Professor DArcy Thompson, Mr. Stevenson pointed out 

 that these coral masses were composed of the skeletons 

 of myriad organisms which had lived in tropical seas, 

 and secreted the limestone of which the skeletons were 

 built up from the lime present in the ocean water. The 

 reefs were not built up by the corals in the sense in which 

 we generally understand building. The builders were 

 unconscious, and showed neither toil nor skill, but, dying, 

 left their skeletons to form a basis on which other genera- 

 tions could repeat the same process of growth and decay, 

 and by the fusing together of the innumerable skeletons, 

 the " bricks " were formed of which the reefs were the 

 aggregates. The coral was shown not to be the " insect " 

 of which one frequently hears, but a near relation of the 

 sea anemone, which lived in colonies, and had the power 

 of secreting a skeleton in its tissues. A description of 

 the coral polyp was given, and illustrated by beautiful 

 models and blackboard sketches. It was shown that the 

 fact of the organisms only being able to live in water 

 where the temperature never fell below 60 degrees 

 practically limited the reef-building corals to the region 

 of the tropics. The difficulty involved in explaining the 

 origin of coal reefs, more especially those annular rings 

 of coral with a lagoon of smooth water in the inside, and 

 on the outside the surging breakers of the fathomless 

 ocean, and which were known as " atolls," was shown 

 to consist in the fact that the corals could not exist at a 

 greater depth than twenty fathoms, while outside these 

 reefs the soundings revealed enormous depths. How, 

 then, had they risen from the deep-sea bottom ? The 

 various theories suggested by early naturalists were 

 touched upon, and the views of Darwin, Agassiz, Le 

 Conte, Semper, John Murray of the Challenger, and Dr. 

 Guppy explained at length the weakness or strength of 

 each being pointed out. The conclusion reached was 

 that of honest Sir Roger de Coverley, " that a good deal 

 might be said on both sides." 



Geological Society of Glasgow. — At the meeting 

 held on November 19th, Mr. Dugald Bell, vice-president, 

 in the chair, the following gentlemen were elected to 

 fill the vacant offices in the council : — As Vice-President, 

 Mr. Forsyth Sommerville : as members of Council, 

 Messrs. William Armour, C.E., William Jolly, F.G.S., 

 R. J. Steele and James S. M'Lennan. Mr. John Young, 

 F.C.S., exhibited specimens and sections, under the 

 society's microscope, of a variety of Ormund stone (a 

 volcanic tuff), enclosing pearl-sinter or pearlite, from 

 Corrieburn, Campsie. In the sections it was seen that 

 the interspaces between the fragments of erupted rock 

 had been penetrated at an after period by a fluid aqueous 

 magma, probably in a heated condition, and which held 

 in solution several mineral elements, such as silica, 

 alumina, lime, and iron. The last three of these appear 

 to have been the first to gather together in the form of 



