XXII U E G I S T E E. 



W U S M A N (II. P.) nnd (t. C. J. Vosmaer. On the structure of some siliceous spi- 

 cules of sponges. I. The styli of Tetliya lyncurium. IB. 



ZEEMAN (p.) presents a paper of Dr. F. M. Jaeger : "A simple geometrical 

 deduction of the relations existing between known and unknown quantities, 

 mentioned in the method of Voigt fur determining the conductibility of heat in 

 crystals." 793. 



— Magnetic resolution of spectral lines and magnetic force. 1st part. 814. 

 Zoology. G. C. J. Vosmaer and H. P. Wijsman: "On the structure of some siliceous 



spicules of sponges. I. The styli of Tethya lyncurium." 15. 



— Sydney J. Hickson : "On a new species of Coralliuin from Timor." 268. 



— Eugen Fischer : "On the primordial cranium of Tarsius spectrum." 397. 



— P. P. C. HoEK : "On the pol3'andry of Scalpellura Stearnsi." 639. 



— H. Steahi. : 'The uterus of Erinaceus europaeus L. after parturition." 812. 

 ZWAAEDEMAKER (h.). On the pressure of sound in Corti's organ. 00. 



— On the ability of distinguishing intensities of tones. 421. 



— On the strength of the reflex-stimuli as weak as possible. 821. 



zwiERS (h. J.). Eesearches on the orbit oi the periodic comet Holmes and on the 

 perturbations of its elliptic motion. 642. 



