April 14, 1905.] 



SCIENCE. 



579 



articulare, which sometimes remains distinct, 

 but more often fuses with the articulare. 

 Other articles are ' Natural and Artificial 

 Parthenogenesis,' by Alexander Petrunke- 

 vitch ; ' The Angle of Deviation from the 

 Normal Vertical Position at which Stems 

 show the Strongest Geotropic Response,' by 

 Julia A. Haynes (a difiicult title for the cata- 

 loguer), and 'Note on the Variation in the 

 Bay Flowers of Rudbeckia,' by Raymond 

 Pearl. 



The Popular Science Monthly for April 

 contains a most important article, ' The Men- 

 ace to Niagara,' by John M. Clarke, showing 

 the entire probability that the American Falls 

 will be destroyed if present plans are carried 

 out. Other articles are ' Sunspots and Weath- 

 er,' by Ernest W. Brown ; ' Medical Research, 

 its Place in the University Medical School,' 

 by Theobald Smith; 'The Problem of Immi- 

 gration,' by Allan McLaughlin ; ' Age and 

 Eminence,' by Edwin G. Smith ; ' Authority 

 in English Pronunciation,' by Edwin W. 

 Bowen, which shows the part dictionaries play 

 in fixing the pronunciation of words, and, 

 finally, ' The Bermuda Islands and the Ber- 

 muda Biological Station for Research,' by 

 Edward L. Mark. In correspondence Olivia 

 R. Fernow discusses the question ' Does High- 

 er Education Unfit Women for Motherhood ' 

 in reply to the somewhat hysterical article by 

 Dr. Smith in March. The number completes 

 Volume LXVI. and has the index. 



SOCIETIES AND ACADEMIES. 



THE NEW YORK ACADEMY OF SCIENCES. SECTION 

 OF ASTRONOMY, PHYSICS AND CHEMISTRY. 



The regular meeting of the section was held 

 ■on Monday evening, January 8, at Fayer- 

 weather Hall, Columbia University. 



The following papers were presented: 



Experiments Relating to the Conductivity of 

 Powders at High Temperatures : Herschel 

 C. Parker. 



When a conducting powder like graphite 

 is mixed with a non-conducting refractory 

 powder, the resistance increases quite rapidly 

 at first ; as the proportion of graphite is de- 

 •creased, then more slowly, and after a time 



reaches a critical point where there is no con- 

 duction or the graphite is destroyed by arcing. 



When the percentage of the conducting 

 powder is low a mechanical separation or 

 ' striation ' takes place on packing in the re- 

 fractory tubes. Besides this an electrolytic 

 separation usually takes place after a time 

 and the conductivity of the mixture is de- 

 stroyed by arcing. 



A very great variety of substances and 

 mixtures were experimented with in the 

 search for a permanent compound of high 

 resistance. 



The Magnetic Susceptibility of Water: A. P. 

 Wills. 



Experiments were made with the large elec- 

 tro magnet of Columbia University to de- 

 termine the magnetic susceptibility of water. 

 With the aid of this magnet, which is one of 

 the largest in existence. Dr. Wills found the 

 coefficient of susceptibility of water to be 

 — 0.72 X 10~**, and also to be independent of 

 the field strength over a range from 4,000 to 

 16,000 C.G.S. units. 



C. C. Trowbridge, 



Secretary. 



SECTION OF BIOLOGY. 



At the March meeting papers were presented 

 by Mr. L. I. Dublin, of the College of the 

 City of New York; Mr. Frederic A. Lucas, 

 director of the Brooklyn Museum; and Pro- 

 fessor F. S. Lee, of Columbia University. 



Mr. Dublin described the history of the 

 germ-cells in Pedicellina americana, giving 

 special attention to the chromatic changes. 

 The somatic number of chromosomes is twenty- 

 two. These bodies behave, throughout, very 

 much as has been described by many workers 

 on other forms ; but in addition there has been 

 observed a peculiar process in connection with 

 the reduction of the chromosomes. These are 

 V-shaped in the somatic cells and in the sev- 

 eral generations of oogonia and spermatogonia, 

 with the exception of what appears to be the 

 last. In this the number is still twenty-two, 

 but they are bar-shaped. These divide and, 

 either before or at the telophase, apparently 

 unite end to end in pairs to form eleven new 

 V's, each bivalent as compared with the earlier 



