XX CON T K N '1' S. 



ZEEMAN (P.). Observations of the mngnetic resolution of spectral lines by means of 

 the method of Fabry and Perot. 440. 



— New observations concerning asymmetrical triplets. 566. 



— Change of wavelength of the middle line of triplets. 574. 2nd part. 862. 



ZERO (The determination of the absolute) according to the hydrogen thermometer of 

 constant volume and the reduction of the readings on the normal hydrogen ther- 

 mometer to the absolute scale. 429. 



Zoology. J. BoEKE: "On the structure of the nerve-cells in the central nervous 

 system of Brauchiostoma lanceolatum". 1st Communication. 86. 



— J. BoEKE and G. J. de Groot : "Physiological regeneration of neurofibrillar 

 endnets (tactile discs) in the organ of Eimer in the mole". 452. 



zwaardemaker (h.) presents a paper of Dr. L. J. J. Muskens : "Nerve influence 

 on the action of the heart. 1st Communication. Genesisof the alternating pulse". 78. 



— On the adsorption of the smell of muscon by surfaces of ditl'erent material. 116. 

 Continued. 12Ü. 



— About odour affinities. 242. 



