Dec, 7, 1888.] 



SCIENTIFIC NEWS. 



583 



this digression, Professor Cossar Ewart went on to remark 

 that when, thirty years ago, the " Origin of Species " was 

 launched on its wonder-working career nothing was 

 known of the ancestral history of the torpedo. Now the 

 position was altered, and he was able to tell them not 

 only what the torpedo's organs had been derived from, 

 but also to trace every step in their life history. To re- 

 deem his pledge, he went on to direct attention to the 

 so-called " pseudo electric " organs of skate. He pointed 

 out that fifty years ago no one ever suspected that the 

 skate was possessed of electric batteries, and that until a 

 few months ago naturalists would probably have ex- 

 pressed surprise had it been suggested that there was 

 considerable diversity in the form and structure of the 

 electrical apparatus of the various members of the skate 

 family. The discovery of the existence of the electric 

 organ of the skate was due to Dr. Stark, of Edinburgh, 

 who read a paper on the subject before the Royal Society 

 of Edinburgh in 1844, but having been labelled by 

 naturalists " pseudo-electric," it had been until quite 

 recently neglected alike by physiologists and naturalists. 

 But the skate's organ was coming to the front again on 

 account of the light it threw on the development of the 

 powerful battery of the torpedo. The discharges from 

 the skate's batteries, though weak, and as far as had been 

 ascertained useless, behaved exactly like the discharges 

 from the torpedo. The skate did not keep its electric 

 battery at each side of the gill like the torpedo, but care- 

 fully tucked away in the tail. He described at length the 

 structure of the electric organ of the skate. Instead of 

 consisting of a series of plates, it consisted of a series of 

 discs or cones fitted into each other like thimbles, and 

 forming a long electric spindle. Each disc consisted of 

 several distinct layers. The first layer, into which all 

 the nerve-fibres pass, was not unlike the electric plate of 

 the torpedo. Altogether, in the electric organ of the skate 

 there might be 25,000 discs, or 50,000 in the two electric 

 spindles. In other skates, instead of the discs, there were 

 numberless cups, each cup having led into it numerous 

 nerve-fibres. He further showed that in other instances 

 the electric organ was composed of muscular cups ; and 

 in the young of the skate the process of development of 

 the muscular tissue into the electrical organ was traced. 

 In the same way, he said, the electric organ of the 

 torpedo, notwithstanding its extreme complexity and 

 remarkable powers, had been formed out of ordinary 

 muscular fibres. For some inscrutable reason, the 

 fibres of certain muscles concerned in moving the 

 jaws of the ancestral torpedoes became more 

 and more modified generation after generation, until 

 they entirely lost their original function, and were so 

 profoundly altered in structure that it was no longer pos- 

 sible to recognise in them the remotest resemblance to 

 muscular tissues. But though he had been able to show 

 that the torpedo's electric srgans had been thus evolved, 

 he had to admit that he only dealt with one of the diffi- 

 culties — he had said nothing of the manner in which the 

 transformation had been effected. 



ROYAL GEOGRAPHICAL SOCIETY. 

 At the meeting held on November 26th, Mr. J.Thomson 

 read a paper on "A Journey to the Atlas Mountains," 

 before a large audience. General Sir B. Walker, K.C.B., 

 presided. 



Mr. Thomson, in the course of his paper, said that the 

 idea of visiting Southern Morocco and the Atlas Moun- 



tains first dawned upon him in 1885. At that time he 

 was engaged in a mission to the Central Soudan, and the 

 infant civilisation he there found flourishing made him 

 desirous of studying its parent resources. Until recent 

 years Leo Africanus, a Moorish traveller, remained the 

 sole authority on the subject of Southern and Central 

 Morocco and the Atlas Mountains. The first really 

 serious attempt to follow in the footsteps of Leo was 

 made in 187 1 by Sir Joseph Hooker and his companion, 

 Mr. Ball, who brought back with them vast stores of 

 botanical information ; but much then still remained to 

 be accomplished. Accompanied by a young friend, Mr. 

 Harold Crichton-Browne, Mr. Thomson said he left 

 England in March, 1888. Arrived at Casablanca, he 

 secured the services of a Moorish soldier, and thus 

 scantily attended they rode overland through the pro- 

 vinces of Shawia, Dukalla, and Abdar to Mogador. As 

 far as the river Tensift the country traversed might be 

 described as a gently undulating, upraised sea-bed, 

 forming a low plateau or broad step, nowhere rising 

 above 500 feet in elevation, and composed in great part 

 of tertiary shell sands. It was a supremely monotonous 

 country, chiefly distinguished by the complete absence 

 of trees and the scarcity of the population — the result of 

 Moorish misgovernment. The travellers passed from 

 areas ablaze with a gorgeous carpet of flowers to tracts 

 of bush and palmetto, or traversed rich plains of black 

 loam, covered with splendid crops of barley and peas, 

 alternating with fields left waste and desolate. Only one 

 stream, the Um-er Rbia, found its way through this 

 region from the mountains. With their arrival at Ten- 

 sift all this disappeared. Here commenced the area of 

 Argan forest, that peculiar and useful oil tree which 

 found sustenance where the more water-loving olive 

 could not live. They obtained their first view of the 

 Atlas mountains on leaving the plain of Akermut, near 

 Jebel Hadid. With their arrival at Mogador, with its 

 gleaming whitewashed houses, they commenced opera- 

 tions for an excursion to the Atlas, and on the 7th ot 

 May they left Mogador with a little party of five men. 

 As travelling in Morocco was a new experience, and the 

 Moorish character an unknown quantity, he judged it 

 best not to plunge straight into the interior until he had 

 satisfied himself to some extent on these points. For 

 that purpose he went by a circuitous route to Saffi 

 through Shiedma. It was well that he did so, for the 

 few days devoted to that trip revealed a state of things 

 among his men which almost reduced him to the verge 

 of despair. Their laziness, insolence, gluttony, and de- 

 ceit were quite a revelation, and he speedily saw that 

 the first essential to successful progress was the settle- 

 ment of the question who was to be master. Arrived at 

 Saffi they directed their steps to the city of Morocco. 

 The route led over the raised sea-bed of Abda, till, 

 reaching the second step of the plateau, they left Abda 

 behind and entered the province of Beled-el-Hummel, or 

 the " Red Country," so called from the colour of its soils, 

 the result of the denudation of the red and purple creta- 

 ceous shales, which here were largely developed. After 

 passing the small salt lake called Zima, on the fourth 

 march, they left behind them the hills of Rahamna and 

 entered the great plain of Morocco, the dried-up bed of 

 some ancient lake. Here for the first time the Atlas 

 range burst upon the traveller in all its massive grandeur 

 as it rose abruptly from the plain and passed by succes- 

 sive irregular terraces into one or two prominent snow- 

 clad elevations, though in the main presenting an even 



