NA TURE 



[May 14, 1896 



investigations suggested by some early work of Pasteur, and also 

 Chatnberland, published in 1879. As is well known, moulds 

 and yeasts are present side by side in large numbers on various 

 fruits, such as plums, cherries, grapes, iStc. ; and Messrs. Klocker 

 and Schionning determined to prove, if possible, that their simul- 

 taneous presence is a mere coincidence, and not evidence of the 

 development of yeast cells from moulds. Comparative examina- 

 tions were therefore instituted of numerous fruits, some of which 

 were simply gathered from the tree, whilst in other cases they 

 were only examined after having been carefully excluded from 

 the outside air for some time by enclosing a small fruit-bearing 

 branch in a specially constructed glass case. Thus, for example, 

 on none of the plums protected from the surrounding air could 

 any yeast cells be discovered, although moulds were present in 

 abundance, whilst on as many as 50 per cent, of those exposed 

 to the air, yeast cells were found along with the moulds. Messrs. 

 ; Klocker and Schiiinning contend that they offered the moulds 

 the most natural and favourable opportunities for the produc- 

 tion of yeast cells in these glass cases, which could be devised, 

 but they failed in every case to make their appearance. Dr. 

 Jorgensen himself, it is only fair to add, appears to be some- 

 what bafHed by the nature of his observations, and in his most 

 recent communication on the subject, frankly confesses that this 

 elaboration of yeast cells from moulds must at present be re- 

 garded as a process in which chance ap]3ears to play an im- 

 portant part, and the circumstances attending which we are yet 

 quite unable to master ! 



M. MoissoN is reported [Ccntr. Zeit.fiir Opt. u. Mech., xvii. 

 6) to have discovered a substance harder than the diamond in 

 the form of a compound of carbon and boron, produced by heat- 

 ing boracic acid and carbon in an electric furnace at a tempera- 

 ture of 5000'. This compound is black and not unlike graphite 

 in appearance, and it appears likely to supersede diamonds for 

 boring rocks, cutting glass, and other industrial purposes. It 

 will even cut diamonds without difficulty, and it can be produced 

 in pieces of any required size. 



According to Prof. J. C. Arthur, the popular idea that ot 

 the two seeds in the spikelet of wild oat, one germinates at once, 

 and the other only after a year, has no foundation in fact. But 

 this is true of the two seeds in the fruit of the "cockle-bur," 

 Xanlhiiim lanadense and slriimarium. The cause of the 

 difierence in the action of the two seeds appears to be con- 

 stitutional and hereditary. 



Only three species of Bears have hitherto been generally 

 recognised by naturalists as occurring in North America, 

 namely the Polar Bear, Black Bear of the Atlantic States, and 

 Grizzly Bear of the Western States, though others have been 

 proposed. In his recently issued " Preliminary Synopsis of the 

 American Bears," Dr. C. Hart Merriani takes a very different 

 view. Dr. Merriam raised the number of American Bears to no 

 less than eleven, dividing those of the "grizzly" type (Urstis) 

 into six species, and those of the "black" type [Eiianlos) into 

 four. Dr. Merriam's synopsis is illustrated by figures of the 

 skulls of the different species. 



M. E. A. Martei,, President of the Speleological Society 

 (Paris), has visited and surveyed the Mitchelstown Cavern in 

 Ireland, and reports on it in the Irish Naturalist for April. 

 Although discovered over sixty years ago, and well known to 

 tourists, this cavern had never before been properly explored. 

 Its chief peculiarity consists in its extensive ramifications, which 

 in one part follow the jointing of the Hmestone so regularly that 

 the plan looks like that of the streets of a town. The total 

 length of the cave exceeds a mile and a quarter, so that it is 

 probably the longest in the British Isles. Mr. Lyster Jameson 

 . furnishes a report on the living animals found in this and other 

 NO. 1385, VOL. 54] 



Irish caves, which mostly fall into three categories — those in- 

 habiting the entrance to the cave as a hiding-place, those that 

 have accidentally been brought in, and those that form its normal 

 fauna. The last consist of a spider and two Colleiuhola, and are 

 interesting as constituting the first true cave-fauna recorded in 

 the British Isles. A description of these forms appeared in 

 previous numbers of the Irish Naturalist and of Spelunca, 



We have received from the Geological Survey of Norway a 

 set of their Reports for the years 1S93, 1894, and 1895, pub- 

 lished by II. Aschehoug and Co., Christiania, at prices which 

 bring them within the reach of every one who may be interested 

 in the subjects of which they treat. The Reports are highly 

 creditable to such a sparsely-peopled country as Norway, and to 

 the Director of its Geological Survey, Dr. Hans Reusch, who 

 seems to thoroughly appreciate the wants of his practical country- 

 men. As the country apparently possesses few organised public 

 departments, the publications of its Geological Survey are com- 

 prehensive in their scope, covering questions of agriculture, 

 forestry, chmate, irrigation, soil, and orography, as well as of 

 mining and geology. The economic aspects of the building- 

 stone and mining industries are well considered and presented 

 to the people for their deliberation and guidance, as well as 

 the purely geological questions of stratigraphy and petrography. 

 Palaeontology, however, is conspicuous by its absence. One of 

 the largest of the Reports deals with roofing-slates, flagstones, 

 and with steatite as a building-stone. It is a pity that the vocaliu- 

 lary of the language is not rich enough to have different words for 

 slate and schist {Skifur represents both); but our own language 

 is equally faulty, or rather misapplied, when the word slate is 

 used in referring to Stonesfield slate, as well as to that of 

 Ballachulish or Llanberis. 



I.\ one of the Reports (No. 14) referred to in the foregoing note, 

 there is an interesting communication by A. Helland, on the 

 depths of the lakes in Jotunheim and Thelemark, as ascer- 

 tained from soundings by himself and others ; but unfortunately 

 all of them have been made in the line of the length of the 

 lakes, none of them transversely, thereby missing a most im- 

 portant clue to the explanation of their origin. He gives longi- 

 tudinal sections of four of the principal lakes in Jotunheim, but 

 the irregularities in the bottoms are not favourable to the glacial 

 erosion theory which he supports ; transverse sections would 

 probably prove more instructive. Of the forty-two lakes men- 

 tioned, no less than twenty-three of them have their bottoms 

 below sea-level. The following series of figures represents the 

 number of feet below sea-level of the first twelve, viz. 14 1 7, 

 1085, 715, 712, 593, 568, 528, 456, 456, 456, 361 and 190. 

 The fir.st is the Hornindals Vand, the surface of which is only 

 177 feet above sea-level, but the bottom is 1417 feet below 

 it ; the second is the Mjosen Vand, the surface of which is 

 397 feet above, and bottom 1085 below, sea-level. The great 

 depth below sea-level seems to militate against the theory that 

 they were eroded by ice. 



In the Bulletin of the Academy of Sciences of Cracow, Dr. 

 L. Natanson contributes a long and elaborate communication on 

 " The Laws of Irreversible Phenomena," and L. Birkenmayer 

 describes a series of observations on the length of the seconds' 

 pendulum in the neighbourhood of Cracow. 



Prok. J. M. Coulter publi.shes, in the " Contributions from 

 the United States National Herbarium," a revision of the North 

 -\merican species of Echiiiocactus, Ccreus, and Opunlia. Fifty- 

 two species are enumerated of the first genus, eighty-two of the 

 second, and loi of the third ; a good many of these are now 

 described for the fir.st time. 



Mr. James Hornell, Director of the Jersey Biological 

 Station, is issuing a series of Microscopical Botanical Sections, 



