548 



NA TURE 



{Aprils 1885 



After the injection of methylic blue, Prof. Ehrlich found in the 

 submucous tissue of the tongue very numerous fibres and fibrous 

 reticula coloured intensely blue which sent processes to the epi- 

 thelial formations, and it was easy to determine that these fibres 

 were the axis cylinders of the sensory nerves. These blue-tinged 

 axis cylinders were found very numerously in the gustatory cuplets, 

 at the basis of which they formed a quite narrow reticula network, 

 whence, then, single fibres ending in knots proceeded anteriorly to 

 the ciliated cells. Network of blue fibres were found very copiously 

 and closely in the cornea. The iris likewise showed blue plexuses, 

 particularly on the anterior side ; on the posterior side only long 

 cancellated reticula were observed. In the muscles, on the 

 other hand, were found only detached blue fibres, the ending 

 of which in the muscle fibre could not be established. The 

 axis cylinders of the motory nerves were, according to this 

 experiment, not coloured by methylic blue during life ; it was 

 only the sensory nerves which reacted to the colouring matter. 

 The vessels, arteries, capillaries, and veins were surrounded by 

 blue plexuses. It could not, however, be decided whether the 

 blue fibres proceeded to the smooth muscle cells. In the retina 

 the nervous layer showed no blue colouring. In the ganglion 

 layer, on the other hand, cells richly charged with blue, and 

 having numerous branching processes, were found, which, too, 

 were in communication with the processes of neighbouring cells. 

 In the mixed nerve stems and in the roots of the nerves no 

 blue fibres were found. The central ends, on the other hand, 

 showed a decided methylic blue reaction, as did also the peri- 

 pherical ends of the sensory nerves. In the brain blue fibres 

 were found only rarely, but were very abundant in the medulla 

 oblongata, while they were wanting, again, in the spinal 

 marrow, and from these results it appears that the colouring of 

 living organs with methylic blue was a very important means 

 towards observing the endings of sensory nerves in them. It 

 must, however, be borne in mind, that the examination had to 

 be prosecuted very rapidly after the colouring process, because, 

 in living tissue, the colouring material got very quickly — in the 

 course of a few minutes — lost by diffusion, and the colouring of 

 the axis cylinders disappeared. — Dr. Benda laid before tire 

 Society several preparations sent by Prof. Adamkiewicz, of 

 Cracau, and gave an explanation of them. After colouring with 

 saffranine, Prof. Adamkiewicz found, in transverse sections of 

 nerve fibres and cords of the spinal marrow within Schwann's 

 sheaths, yellow to brown coloured crescents, which were sec- 

 tions of peculiar fusiform cells, and in the opinion of Prof. 

 Adamkiewicz represented hitherto unknown parietal cells, lying 

 within the nerve fibres, distinguished by their saffranine reaction. 



Meteorological Society, March 3. — Dr. Hellmann spoke 

 on the rainfall of Germany. Aftei a short reference to 

 the rain-maps of Germany, hitherto published, which had 

 been in some degree prepared from insufficient material and 

 according to inadequate methods, he set forth the points of view 

 which had determined the arrangement of sixty new rain- 

 stations. By grouping and comparing the new annual observa- 

 tions with those of neighbouring stations, which ranged over a 

 long series of years, he was now in a position to draw a number 

 of important conclusions. He was able to establish, for ex- 

 ample, that the eastern part of North Germany, and, in par- 

 ticular, the right bank of the Oder, was not, as had hitherto 

 been supposed, a dry district, at least not over its whole area, 

 seeing that there were several stations within that section show- 

 ing moderate amounts of rain. It was further ascertained that 

 the views formerly prevalent respecting the rainfall in moun- 

 tainous regions were not correct, each mountain chain not having 

 been considered separately when inductions were made from the 

 data hitherto accumulated, in which other essential factors came to 

 be mixed up with that of the elevation and vitiated the result. 

 In regard to the yearly distribution of rain, Dr. Heilmann's 

 investigations showed that the great North German plain was 

 embraced within the region of the summer rains ; that the 

 curve of rain-quantity and rain-frequency sank from January to 

 April, reaching its minimum in that period, whence it rapidly 

 rose to its maximum, which was attained in the summer months, 

 and then sank slowly to its winter values. The maximum of 

 rainfall in the furthest east occurred in June ; immediately 

 to the west in July ; still more to the west in August ; 

 in Sleswick, later still ; and in Heligoland, not till November. 

 A closer examination of the rain-curve in North Germany 

 showed that it consisted of two maxima, with a depression of 

 greater dryness occurring in July. A similar double maximum 

 was likewise found in South Germany and in North-West 



Germany. The first and greater rain maximum occurred with the 

 recurrence of cold in June, and, altogether, the curve of 

 temperature in North Germany showed a perfectly correspond- 

 ing, inverse course with that of the rain-curve. The moun- 

 tains of Germany — the Sudetic Mountains, the Taunus, the 

 Harz, the Thuringian Forest — which were all separately investi- 

 gated in respect of their rainfall — showed an inverse course in 

 the yearly rain-curve as compared with that of the plain. In the 

 mountains, the maximum of rainfall occurred in winter, whence 

 the curve sank in spring, then rose to a small secondary maxi- 

 mum in summer, sank thereafter, and finally rose to its 

 year's maximum in winter. In respect of the absolute rain 

 maxima the observations hitherto made showed that for Ger- 

 many the month's maximum amounted to about 9/45 inches, and 

 that the greatest daily rainfall amounted for the plain to about 

 S'9 1 inches, and for the mountains to from ySS to 9/45 inches. 

 The greatest hourly rainfall hitherto observed was 2 '96 inches. 

 Dr. Hellmann exhibited a self-registering rain-gauge by 

 Hottinger, and explained its construction. — Dr. Kremser de- 

 scribed an ascent of the Schneekoppe made by him on January 

 3 and 4, 1S85, and submitted some meteorological observa- 

 tions taken by him on that occasion. On the height of the ridge 

 he had clear sunshine over head, while the mountains under him 

 lay enveloped in fog, the contour of which he was thus in a 

 position to observe. In the Riesengrund, into which the sun 

 shone clearly, he saw a huge pillar of fog, the upper end 

 of which was curved into a whirling shape, resembling the 

 column of smoke in an ascending air-current, as described in 

 Herr Vettin's experiment {vide Nature, vol. xxxi. p. 284). 

 On the Schneekoppe he saw the brown-red ring around 

 the sun in a state of remarkable completeness. About 10° 

 around the sun was a brilliantly white space, which passed 

 through yellow and yellow-brown into the copper-coloured ring, 

 6|° broad. At the point where it touched the horizon the two 

 limbs showed different tints. Before sunrise the moon was 

 densely surrounded by a violet halo, which extended to about as 

 far as 1 8° from the moon, and gradually passed into the dark- 

 blue sky. The observer stationed on the Schneekoppe related 

 that he likewise had often, for now nearly a year, seen the 

 violet halo around the moon. Lastly, it was to be stated that, 

 like all other exposed objects, the telegraph poles were covered 

 with immense masses of hoar-frost, so that they showed a 

 diameter reaching to 1 m., and the rain-gauges were also so 

 heavily covered with the hoar-frost as to be practically useless. 



CONTENTS p AGE 



Tredgold's "Carpentry" 525 



The Myriopods of Austria 526 



Our Book Shelf : — 



Turner's " Examples in Heat and Electricity " . . . 526 



Knox's " Differential Calculus for Beginners " . . . 527 

 Letters to the Editor : — 



Rock-Pictures in New Guinea. — Dr. Emil Metzger 527 

 Mr. Lowne on the Morphology of Insects' Eyes. — 

 Benjamin T. Lowne ; George J. Romanes, 



F.R.S 528 



How Thought presents itself among the Phenomena 



of Nature. — Prof. G. Johnstone Stoney, F.R.S. 529 



Magnetic Disturbance. — G. M. Whipple .... 530 



The Samsams. — Prof. A. H. Keane 530 



Meteor. — H. Sadler 530 



Steel Guns 530 



On the Formation of Snow Crystals from Fog on 



Ben Nevis. By R. T. Omond 532 



Bird Architecture. By Charles Dixon 533 



The Institution of Naval Architects 533 



The Eggs of Fishes. By Prof. Mcintosh, LL.D., 



M F - R -S 534 



Notes 537 



Our Astronomical Column : — 



Ancient Occupations of Aldebaran 539 



Barnard's Comet 540 



Astronomical Phenomena for the Week 1885, 



April 12-18 540 



Geographical Notes 540 



On the Salinity of the Water in the Firth of Forth. 



By Hugh Robert Mill, B.Sc, F.C.S. (Illustrated) 541 



The Pearl Fisheries of Tahiti 545 



Societies and Academies 545 



