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NATURE 



[February 22, 1900 



Prof. J. Massau, of Ghent, sends us a lithographed paper 

 on the graphic integration of partial differential equations. It 

 is divided into three chapters, dealing with integration by 

 elements, integration equations of the first and second orders 

 and of simultaneous linear equations by means of character- 

 istics, and applications to variable motion of fluids, under 

 which latter heading may be included finite wave-motion, and 

 the formation of bores. A somewhat analogous problem, viz. 

 the approximate integration of partial differential equations of 

 the first order of the ioxm p -V qf {x , y)=o, subject to the condition 

 that f{x, y) is real, finite, single valued, and continuous in an 

 assigned region C, and that q is also continu jus, is treated by 

 Dr. C. Severini in the Rendiconti del R. Istittito Lombardo, 

 xxxii. 19, 20, who shows that the integral of the equation can 

 be represented to any degree of approximation by means of 

 a rational integral polynomial in x and y. 



Stimulated by the disastrous Constantinople earthquake of 

 July 10, 1894, the Sultan of Turkey ordered that observations 

 of earthquakes should be regularly made within his empire, and 

 the Director of the Meteorological Observatory was fortunate 

 ■enough to secure the assistance of Dr. G. Agamennone, of 

 iRome {see Nature, vol. lii. p. 4). During the years 1895 and 

 1896, this well-known seismologist created an organisation for 

 the collection of earthquake records over the whole of the south- 

 .east of Europe and Asia Minor, and the results for 1895 and 

 the early part of 1896 were published in monthly bulletins, 

 issued by the observatory. For reasons, which are unknown , 

 the authorities refused to continue printing these valuable lists, 

 and, on the departure of Dr. G. Agamennone, the whole organ- 

 isation was allowed to lapse. Fortunately, a copy of the records 

 for 1896 was preserved, and has recently been published in 

 Gerland's Beitrdge zur Geophysik. This valuable paper con- 

 tains a list of more than 400 earthquakes, as well as detailed 

 descriptions of the more important shocks. It is a monument 

 •of what can be accomplished, even in a semi-civilised country, 

 by the energy of one man. 



Dr. D. G. Elliot is continuing his studies in North American 

 mammals in the Publications of the Field Columbian Museum ; 

 the last part with which we have been favoured treating of 

 collections from Oklahoma and Indian Territories. A feature 

 of Dr. Elliot's is the attention bestowed on the habits of animals, 

 the present part describing the nests of the wood-rats {Neotoma). 



To the Mentor ias de la Sociedad Cientifica " Antonio Alzate,^' 

 issued at Mexico, Prof. R. Manterola contributes a paper on 

 longevity in connection with mental work. The author divides 

 professions into three groups, according to their influence on 

 longevity ; and it may be satisfactory to scientific workers to 

 learn that they occupy a high position in the most favoured 

 group. In mental workers the general average of life is stated 

 to be above 68 years, and the average of men of science, 

 lawyers and historians more than seventy. 



In the December number of Natural Science, Mr. Barrett- 

 Hamilton draws an interesting parallel between the occurrence 

 of portions of the skin of the "last of the Ground- Sloths" in 

 Patagonia, and of similar remains of Lemmings in a Portuguese 

 cave. The latter animals are now unknown south of lat. 

 58" 30', yet the Portuguese remains present the appearance of 

 having belonged to animals recently dead. The inference is 

 that even in comparatively damp climates, the shelter of a cave, 

 with abundance of dry dust, is sufficient to preserve some of the 

 soft parts of animals for very long periods. 



We have received from the trustees of the Indian Museum, 

 Calcutta, a newly published "Guide" to the collection of 

 fishes exhibited in what was formerly the library of the Geo- 

 logical Survey. Dr. A. Alcock is the author of this useful 



KG. 1582, VOL. 61] 



little pamphlet, which not only contains a well-written dis- 

 sertation on the structure of fishes in general, as well as a 

 classified synopsis of the families, but has a special section on 

 the geographical relations of the marine fishes of India. 

 Among the exhibits are models of deep-sea fishes ; and it may 

 be suggested that a similar series would be of great interest 

 if added to our own national collection. 



In the February issue of the Quart. Journ. Microscop. Soc, 

 Mr. J. P. Hill, of Sydney, continues the account of his im- 

 portant researches into the embryology of the marsupials. His 

 discovery of the existence of a distinct placenta in the Bandi- 

 coots (Peraineles) will be fresh in the minds of our readers, 

 and likewise the inference that the retention of such a structure 

 indicates a primitive condition. His subsequent investigations 

 have led the author to the significant conclusion that the unno- 

 genital organs of the Bandicoots are in a condition which may 

 be described as persistently embryonic, and thus much more 

 primitive than in any other known marsupial. Accordingly, all 

 the available evidence points to the view that the marsupials 

 originally developed a placenta, which has been aborted 

 in the more specialised forms. The .second part of the present 

 communication deals with the fatal membranes of one of the 

 Wallabies. — To the same journal Mr. H. M. Bernand con- 

 tributes a paper on the structure of the retina of the eye in the 

 Amphibia, in the course of which he is led to conclude that the 

 so-called "cones," in place of being important sensor organs, 

 are nothing more than stages in the development of new " rods." 



In these columns mention has already been made of the 

 discovery of a horn of the extinct Aurochs or Ur {not the 

 Bison) in a peat bog in Lower Pomerania. This remarkable 

 specimen Dr. Nehring now describes and figures in ihe Deutsche 

 Landwirtschaftliche Presse of February 10, In the course of 

 this article the author mentions that the Aurochs (of which our 

 domestic cattle are the descendants) survived on the Continent 

 till 1627, and that examples of its enormous horns, sometimes 

 mounted as drinking-cups, were preserved in many inns, 

 churches, and castles, especially in South Germany and Alsace- 

 Loraine, till a comparatively recent date. In 1550 Conrad 

 Gesner, for instance, mentions having seen skulls, with the 

 horns, of Aurochs at old hostels in Worms and Mayence. Till 

 as recently as the first French Revolution, two Aurochs' horns 

 were preserved in Alsace, the one in the cathedral at Stras- 

 burg, and the other in the cellars of the episcopal palace at 

 Zabern. The first measured 6^ feet in length, while the second 

 held four litres. Since both are now lost, the newly-discovered 

 sub-fossil specimen is of priceless value. 



It appears from the annual meeting, on January 28, of the 

 Russian Institute of Experimental Medicine (Pasteur Institute) 

 that its activity is steadily developing. The number of its pro- 

 vincial branches has been increased this year by a branch opened 

 in Transbaikalia for the study of rinderpest in East Siberia. 

 More than fifty' papers, some of which are of great value, have 

 have been read at the meetings by Drs. Nencki, Pavloff, 

 Vinogradski, Semenoff, Lukianoff, Vladimiroff, Dzerzgowski, 

 Schultz, and their pupils. The most important of them was 

 perhaps the paper, read by Prof. A. M. Levin at the annual 

 meeting, on the bacterial origin of scurvy. No less than 80,000 

 scurvy patients were registered last year in the provinces which 

 had suffered from famine (755,000 for the last eleven years). 

 The epidemical character of scurvy became well established by 

 the last few years' observations, and Prof. Levin eventually ob- 

 tained pure cultures of the bacteria of scurvy. They have the 

 shape of rods, with rounded ends, have no cilia and give no 

 spores. They are similar to diplococci, and belong to the group 

 of bacteria which are well known as the cause of chicken- 



