NOTEMBEB 5, 1915] 



SCIENCE 



653 



sure on the polymorphic transitions of 30 

 substances. 



4. On Isotliermally Conjugate Nets of Space 



Curves: Gabriel M. Geeen, Department of 



Mathematics, Harvard University. 



A necessary and sufficient condition that a 



conjugate net of curves on a surface be iso- 



thermally conjugate is that at each point of 



the surface the pair of axis tangents, the pair 



of associate conjugate tangents, and the pair 



of anti-ray tangents he pairs of the same 



involution. 



6. The Role of the Liver in Acute Poly- 

 cythaemia: The Mechanism Controlling the 

 Red Corpuscle Content of the Blood: Paul 

 D. Lamson, Pharmacological Laboratory, 

 Johns Hopkins University. 

 There is in the body a mechanism for regu- 

 lating the red coi-puscle content of the blood; 

 this mechanism is under nervous control, re- 

 sponding to nervous, chemical and emotional 

 stimuli; the adrenal glands play a part in this 

 mechanism, and the liver is the seat of the 

 changes which increase the number of red cells, 

 partly by a reduction in plasma volume, and 

 partly by bringing cells into the circulation 

 which are not normally present. 

 6. The Potentials at the Junctions of Salt 

 Solutions: Duncan A. MacInnes, Labora- 

 tory of Physical Chemistry, University of 

 Illinois. 



The author calls attention to the fact that 

 the liquid junction potential ^^ of a concen- 

 tration-cell of the type Ag + AgCl, K01(C,), 

 KCl (C„), AgCl + Ag can be derived from 

 measurements of its electromotive force E and 

 of the cation-transference number n„ with the 

 aid of the equation Ej^/E = (2nc — l)/2n<. 

 This equation involves only the assumption 

 that the work attending the transfer from one 

 concentration to the other of one equivalent 

 of ion is the same for the cation as for the 

 anion. The author substantiates this assump- 

 tion by showing that this equation, when 

 applied to the electromotive force data of Jahn, 

 leads to nearly the same values of E — E^^ 

 (which should equal the difference in the two 

 electrode-potentials) whether the electrolyte be 

 KCl, NaCl or HCl. 



7. A Statistical Study of the Visual Double 

 Stars in the Northern Shy: Robert G. 

 AiTKEN, Lick Observatory, University of 

 California. 



At least one in every 18, on the average, of 

 the stars as bright as 9.0 magnitude in the 

 northern half of the sky is a double star visible 

 with the 36-inch telescope. Close visual double 

 stars are relatively more numerous in the 

 Milky Way than elsewhere in the sky, and 

 visual double stars as a rule revolve in rela- 

 tively small orbits. Close visual double stare 

 are rare among stars of either very early or 

 very late spectral class. 



8. Walnut Mutant Investigations: Ernest B. 

 Babcock, Division of Genetics, Department 

 of Agriculture, University of California. 

 The mutation takes place in female flowers 



only and appears in the first generation after 

 the mutation occurs but on crossing with the 

 species type it is completely recessive in the Pj 

 generation and the nature of the mutation is 

 such that only certain genetic factors are 

 affected without having the chromosome num- 

 ber disturbed. 



9. Hereditary Fragility of Bone : C. B. Daven- 

 port and H. S. Conard, Carnegie Institu- 

 tion of Washington and Grinnell College, 

 Iowa. 



Of a parent who early in life was affected 

 with brittle bones at least half the children will 

 be similarly affected, but if neither parent, 

 though of affected stock, has shown the tend- 

 ency, then expectation is that none of the chil- 

 dren will have brittle bones. 



E. B. Wilson 



SPECIAL ABTICLES 

 ON the occurrence in the southern hemis- 

 phere OF the basking or bone shark, 



cetorhinus maximus 

 Since it does not seem generally to be known 

 that this giant elasmobranch is found in 

 southern waters, it may be of interest briefly 

 to give the following data which have been 

 noted from time to time in the course of other 

 ichthyological studies. 



The old writers thought that this great beast 

 was confined to the far north Atlantic and to 

 the Arctic Ocean. Of these, Friedrich Faber 



