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SCrENCE. 



[N. S. Vol. V. No. 119; 



of California are described by W. Lindgren. 

 These include granites proper and the grano- 

 diorite, which is characterized as an intermedi- 

 ate type, neither a normal diorite nor a granite, 

 but occupying a place between normal quartz- 

 mica-diorite and quartz-monzonite; also normal 

 diorite and gabbro from smaller areas inclosed 

 in granodiorite or granite, or on the contact 

 between them and the schists. It is concluded 

 that all of the granite rocks are later than the 

 altered sedimentary rocks described and the 

 augite-porphyrite, though the relative age of 

 the granite, granodiorite, diorite and gabbro, 

 is not decisively settled. ' ' The probability is 

 that the intrusion both of the granite and of the 

 granodiorite was accompanied by minor intru- 

 sions of acid and basic magmas, and that there 

 are diorites, pegmatites and aplites, of the age 

 of the granodiorite and of that of the granite, 

 the latter being the older rock." 



R. S. Tarr discusses the difference in the 

 climate of the Greenland and American sides of 

 Davis's and Baffin's Bay. The former name is 

 proposed for the bay between Labrador and 

 Greenland, south of Davis' Straits. When in 

 the Arctic region in the summer of 1896 the 

 author noted the remarkable difference in 

 climate of the two localities, the eastern side 

 being distinctly warmer and at a given time 

 more free from snow and ice than the western. 

 The cause of this is found largely in the ocean 

 current moving northward on the Greenland 

 coast, to which is added the influence of the 

 winds. Remarks are also made on the changes 

 of level of Baffin Land and its relation to glaci- 

 ation. E. C. Case describes the foramina per- 

 forating the cranial region of a Permian reptile. 

 The paper is accompanied by a series of cuts. 



John Trowbridge and Theodore W. Richards 

 discuss the temperature and ohmic resistance of 

 gases during the oscillatory electric discharge. 

 The paper gives the result of a series of experi- 

 ments which have led the authors to conclude 

 that " a mass of gas at low tension contained in 

 a capillary tube may act as though it opposed a 

 resistance of only five or six ohms to the spark 

 of a large condenser. ' ' Pliicker tubes were em- 

 ployed with aluminum electrodes and the volt- 

 meter allowed of measuring the voltage up to 

 1,800 volts and above by approximation. A 



battery of from five to ten thousand storage 

 cells was employed with a large condenser and 

 a water resistance interposed of from five to 

 fifty megohms. A series of tables give the 

 number of half oscillations corresponding to 

 varying resistances and capacities. Experi- 

 ments were made with hydrogen and nitrogen 

 gas in particular, and the evidence reached 

 from them is summed up as follows : 



' ' (1) The resistance of a gas at low pressure to 

 the oscillatory discharge is equivalent to only a 

 very small ohmic resistance. (2) This resist- 

 ance is in general greater the less the quantity 

 of electricity. (3) Down to a very small pres- 

 sure this resistance decreases with the tension 

 of the gas. (4) The form of the tube has an 

 important effect upon the resistance of the gas. 

 (5) With the oscillatory discharge it is evident 

 that the electrodes produce far less effect than 

 with the continuous discharge." Certain con- 

 clusions are also suggested as to the effect of the 

 dissociation in diminishing the resistance of the 

 gas experimented upon, thus tending to ex- 

 plain the difference of the spectra obtained 

 under different conditions. In a following arti- 

 cle, discussing whether a vacuum conducts elec- 

 tricity, Trowbridge states that his experiments 

 lead him to believe that ' 'a disruptive discharge 

 of electricity encounters its chief resistance at 

 the going-over layer between the electrodes 

 and the medium, and that during the discharge 

 in a highly rarified medium very little resist- 

 ance is encountered." 



I. C. Russell discusses the plasticity of glacial 

 ice, with reference to recent experiments by 

 McConnell, Kidd and Miigge. The observa- 

 tions made of the optical structure of the ice 

 lead to the conclusion that "the yielding of 

 glacial ice to pressure is due to movements 

 along gliding planes in the granules of which it 

 is composed." The closing article is by O. C. 

 Marsh on the affinities of the Cretaceous bird, 

 Hesperornis. He recalls his early conclusions 

 that the hesperornis was allied to the ostriches 

 and shows that they are confirmed by the re- 

 cent discovery of a specimen showing feathers 

 in place and these feathers are the typical plu- 

 mage of an ostrich. In the notes which follow 

 A. E. Verrill states that in the examination of 

 a mass of the integument from the supposed 



