256 



NA rURE 



[Jan. 10, 1884 



tained that they devslopel themselves out of continuations of 

 the ganglion cells. Whether and in what manner they cnme 

 later into confluence with the optic fibres proceeding from the 

 brain was a point which mu^t be reserved for further investiga- 

 tion. Prof. Waldeyer deemed it not impossible that the optic 

 fibres growing out of the ganglion cells penetrated into the brain, 

 and there merged into the central ganglion. Thereafter was 

 developed the so-called molecular layer. This name had been 

 given to it in consequence of its finely granul.ar appearance 

 under slight enlargement. With the povvrful amplification 

 which was now customary it was, however, at the present day, 

 universally recognised as consisting of an extremely fine network 

 of the most delicate filaments. In the middle of this layer Ilcrr 

 Koganei had found a series of round cells which, having 

 issued from fundamental cells, formed the mother-cells of this 

 layer. Since it was now InovAn that cellular protoplasm con- 

 sisted of a reticular coating and fluid contents, it became intel- 

 ligible how, from the protoplasm of the series of m ither-cells 

 occupying the middle zone, the fine fibrous net of the molecular 

 layer was formed by more vig )rous developoicnt of the proto- 

 plasmic coating and the proportionate reduction of the liquid 

 contents. In the further development of the embryonal retina 

 there now appeared the internal granular layer with the median 

 granular layer, followed, shortly after, by the external granular 

 layer. Both granul.ar layers developed themselves from the 

 fusiform fundamental cells through the latter 1)ecoming round 

 .ind partially emitting continuations. In this manner they 

 formed themselves into ganglion cell-', as the granules of the 

 granulir layer must be considered. The median granular layer 

 was in the highest probability a layer of fibre-nets intercalating 

 itself, like those of the molecular layer. In the granular layers, 

 liesides round and gan;.;lion cells, fu-iform cells were also met 

 with. These fusiform cells, by vigorous longitudinal growth, 

 developed themselves into supporting fibres (Sliilzfasirii), 

 flattened themselves at their extreme ends, and by superitnposi- 

 tion of their terminal lamina? torn ed the membrana limitans ex- 

 terna. On the development of this last membrane the ganglia or 

 granules of the granular Layer began to send continuations outwards 

 striking through the membrana limitans, which, therefore, very 

 soon appeared occupied with the little blunt endings (Stidiipfchcii). 

 These again grewto be granular interior members of the rods 

 and pins that, finally, developed the hyaline external members 

 which were powerfully refractive and cylindrical, or cone-shaped, 

 the la t members in the series of the development of retina ele- 

 ments. At this point the fact, of supreme importance to the physio- 

 logist, was established, that new-born animals only began to see 

 when the exterior members of the rods and cones were deve- 

 loped. From the foregoing observations, Prof. Waldeyer 

 deduced an important general conclusion, which had equal 

 applicability to the brain as to the retina. The development of 

 the retina demonstrated that all its morpholojic.il constituents, 

 the ganglion cells, the nerve fibres, and the supporting fibres were 

 developed from the same fundamental cells. The supporting 

 fibres of the retina, and in like n anner the neuroganglia of the 

 brain, must consequently be classed as belonging to the nervous 

 system, and having nothing in common with the ligamental 

 tissue. They were nervous apparatus, which only did not per- 

 form nervous functions. In the case of regenerative processes, 

 however, they played an important part. It was known that 

 highly differentiated tissues were not capable of regeneration, 

 which was therefore impossible in the case of ganglion cells and 

 nerve fibres. Supporting fibres and neuroganglia, on the other 

 hand, were cap.able of regeneration, and, being developed from 

 neurously constituted cells, were also capable of undertaking 

 nervous functions or of furtherdifferentiating themselves for those 

 higher functions. This highly important question deserved a very 

 thorough investigation. 



Vienna 

 Imperial Academy of Sciences, October 11, 1883.— On 

 the genetic formation of the flora of New Zealand, by C. von 

 Ettingshausen. — On i.sobutyl-biguanidine, by A. Smolka. — On 

 the Diatomaceje collected by the Austro-Hungarian North Polar 

 Expedition in Franz- Josef Land, by A. Grumov. — On gravita- 

 tion, by A. larolimek. — On the comet discovered by Brooks, by 

 E. Weiss. — On some spectral analytical researches carried out 

 with the large refractor of the Vienna Observatory, by C. H. 



Vngel. 



October 18, 1883. — On the theory of diffusion of gases ; 

 part ii., dealing with the diffusion of a gas into itself, by L. 

 Boltzmann. — On the quantity of work which can be obtained by 



chemical combination, by I.. Boltzmann. — On the forms and 

 chemical composition of the scap iliih series, by F. Tschermak. 



Octo'^ier 25, 1S83. — On roemerite, botryogen, and natural 

 magnesia iron vitriol, by T. Blaas. — Ichlhyological contributions, 

 (thirteenth paper), by T. Steindachner. 



November 8, 1883. — Contributions to general nerve- and 

 mu-cle-physiology ; xii., on the change of the electromotor 

 behaviour of muscles produced by electric irritation, by E. 

 Hering and W. Biedermann. — Supplement to his paper on the 

 quantity of work v\ hich can be obtained by chemical combina- 

 tion, by 1.. Boltzmann. — On a series of new mathematical prin- 

 ciples, by O. Simony. — Report on the French Expedition sent 

 to the Manihiki Islands to observe the solar eclipse of May 6, 

 1S83, by T. Palisa. 



November 16, 1883. — On the role of the inferior asteroids, 

 by F. Chapel. — On the intercellular spaccs of the epithelium of 

 the Polmonata, by A. N.ilepa. — On the axis of the tail of the 

 comet 1827 III., by T. von Hepperger. 



November 22, 1883. — Contribution to general nerve- and 

 muscle- physiology ; xiii., on Du Bois Keymond's researches 

 on the secondary electrical phenomena of muscle, by E. Hering. 

 — On the genetic formation of the flora of Ilong Kong, by C. von 

 Ettingshausen. — Contributions to the theory of respiratory intier- 

 vation (fourth communication), by Ph. Knoll. — On the species, 

 sub-species, varieties, and hybrids of the section Ptamica of the 

 Achillea genus, by A. Heimerl. — Contributions to the kno.<'lelge 

 of the fishes of the Adria, by E. Steindachner and G. Coloni- 

 batovic. — Contributions to the knowledge of the chemical com- 

 position of starch-granules, by B. Bruckner. 



December 6, 1883. — On a vertebral syno-tosis in Salamandra 

 maculosa, .Saur., liy T. H. List. — On the mechanism of the 

 distant action of electrical forces, by T. Odstrril. — Calculaii m 

 of the altitude of the pole and of the azimuth at the Krem-- 

 miinster Observatory, by W. Tmter. — Report on his geological 

 researches carried out in the western Balkan and the adjacent 

 regions, by F. Toula. — Determination of the orbit of the Russia 

 planet (232), by N. Herz 



December 13, 1883. — Histological and physiological studies 

 on the organ of taste, by O. Drasch. — On the satellite curves 

 and satellite planes, by G. Kohn. — Stru^'gle of physical axioms, 

 by T. Schlesinger. 



CONTENTS Page 



American Geology. By Arch. Geikie, F.R.S. . . . 233 

 Our Book Shelf:— 



Mme. Royer's " Atlriction et Gravitation d'apres 



Newton " 235 



" Electrotechnisches Jahrbuch von der Electrotech- 

 nischen Gesellschaft in Frankfurt am Main " . 235 



Letters to the Editor :— 



What are the Saccopharyngoid Fishes? — Theo. Gill 236 

 The Mildness of the Season. — Viator ..... 236 

 River Thames — Abnormal High Tides. — J. B. Red- 

 man 237 



Deafness in White Cats. — Joseph Stevens .... 237 

 Teaching Animals to Converse. — J. S. B. .... 237 

 On the Absence of Earthworms from the Prairies 

 of the Canadian North-West.— Richard M. Har- 

 rington 237 



Merrifield's " Treatise on Navig,ation." — John Merri- 



field 237 



An American Rothamsted. By Prof. W. Fream . 238 

 Edelmann's Electrometer ( ff-'ii'/; /)zafr<;;«j) .... 239 

 Gleanings from the Reports concerning the Erup- 

 tion of Krakatoa. By E. Metzger ( With Cliarl) . 240 



Notes 244 



Our Astronomical Column : — 



The Solar Motion in Space 246 



'1 he Late M. Vvon Villarceau ... 246 



The English Circumpolar Expedition. By Capt H. 



P. Dawson, R A 247 



The Evidence for Evolution in the History of the 



Extinct Mammalia, II. By Prof. E, D. Cope 248 

 The Remarkable Sunsets. By D. Wetterhan ; G. A. 

 Rowell ; George F. Burder ; Thos Wm. Back- 

 house ; E. Metzger 250 



University and Educational Intelligence 252 



Scientific Serials 252 



Societies and Academies 253 



