GONTEN ES. EX 
LENGTH OF ILLUMINATION (The relation between the intensity of light and the) in the 
phototropic curvatures in seedlings of Avena Sativa. 230. 
LINDENIOPSIS. A new subgenus of the Rubiaceae. 123, 
LOCKYER’s 35-year period (On) in the solar activity. $42. ° 
LONDEN (D. M. vAN) and ©, WiNkrer. About the function of the ventral group 
of nuclei in the thalamus opticus of man, 295. 
LORENTZ (H. a.) presents a paper of Dr. L. S. Ornstein: “Calculation of the 
pressure of a mixture of two gases by means of GrBBs’s statistical mechanics.” 116. 
— presents a paper of Dr. O. Postma: “On the kinetic derivation of the second 
law of Thermodynamics.” 303. 
— presents a paper of Prof. W. Vorer: “Remarks on the Leyden Observations of 
the ZEEMAN-eftect at iow temperatures.” 360. 
— presents a paper of Dr. L. S. ORNSTEIN: “Statistical theory of capillarity.” 526. 
— presents a paper of Mr. J. J. van Laar: “On the solid state.” 765. 
— presents a paper of Dr. O. Postma: “On the calculation of the pressure of a 
gas by the aid of the assumption of a canonical ensemble.’ 781. 
— presents a paper of Dr. J. H. Meerzpure: “On the motion of a metal wire 
through a piece of ice.” II. 886, 
MAGNETIC FIELD (The law of shift of the central component of a triplet in a). 473. 
MAN (About the function of the ventral group of nuclei in the thalamus opticus of). 295. 
— (About the development of the urogenital canal (urethra) in). 494. 
MARTIN (K.). The age of the layers of Sondé and Trinil on Java. 185. 
Mathematics. L.E.J. Brouwer: “About difference quotients and differential quotients.” 59. 
— JAN DE VRIES: “Congruences of twisted curves in connection with a cubic 
transformation.” 84. 
— P. H. Scuourn: “On groups of polyhedra with diagonal planes derived from 
polytopes.” 277. 
— J. A. Barrau: “On triple systems; particularly those of thirteen elements.” 290. 
— M. Sruxvaerr: “On certain twisted sextics.” 346. 
— J. A. Barrav; “On the combinatory problem of STEINER.” 352. 
— P. H. Scnoure: “On fourdimensional nets and their sections by spaces.” 3rd 
part. 380. 4th part. 543. 
— W. Kapteyn: “On a theorem of PAINLEVÉ’’, 459. 
— Jan DE Vries: “On bicuspidal curves of order four”. 499. 
— Jan ve Veres: “On curves of order four with two flecnodal points or with two 
biflecnodal points”. 568. 
_ — Jan DE Vries: “On curves which can be generated by projective involutions 
of rays”. 576. 
— Lucien Gopraux: “The types of bilinear oo” -complexes of MES in Sp,”. 625. 
— H. pe Veres: “The plane curve of order 4 with 2 or 3 cusps and 0 or 1 nodes 
as a projection of the twisted curve of order -4 and of the ‘st species.” 627. 
— J. C. Kiuyver: “An integral-theorem of GEGENBAUER”. 749, 
— Jan De Vries: “A family of dilferential equations of the first order”. 756: 
