XXXIV CON TENDS 
VENTRICLE (Ventricular fibrillation and ,,Gehdufte’” extrasystoles of the) 
excited by the ,,Erregung” consequent on an artificial auricular systole. 533. 
— (On the artificial extra-pause of the) of the frog’s heart. 542. 
VERKADE (P. E). On the action of micro-organisms on organic com- 
pounds. II. The solubility of some organic acids in fatty oils. 783. 
Verstuys (J.) and R. DeMorr. Die Verwandtschaft der Merostomata 
mit den Arachnida und den anderen Abteilungen der Arthropoda. 739. 
VerzarR (F.) and W. STORM VAN LEEUWEN. Concerning the sensitivity 
to poisons in animals suffering from avitaminosis. 1170. 
VISUAL sensations. 338. 
VOLCANO RuANG (Sangi Islands) (Crystallization and resorption in the 
magma of the). 561. 
VOLTERRA (On the theory of hysteresis according to). 663. 
VoruMes (On the equation of state for arbitrary temperatures and). Analogy 
with PLANCK's formula. II. 887. 
VORTEX MOTION (On the resistance of fluids and). 774. 
Vries (HENDRIK DE) presents a paper of Dr. B. P. HAALMEYER: “On 
elementary surfaces of the third order.” (Stk comm.). 920. 
— presents a paper of Dr. J. W. N. Le Heux: “Explanation of some 
interference curves of uniaxial and biaxial crystals by superposition of 
elliptic pencils.” 1223. 
VRIES (JAN DE). An involutory transformation of the rays of space 
which is defined by two involutory homologies. 462. 
— An involution of rays defined by a congruence of REYE and an 
involutory homology. 466. 
— presents a paper of Prof. K. W. Rutgers: “Degenerations in linear 
systems of plane cubics.” 797. 
— Two representations of the field of circles on point-space. 1323. 
VucT (D. vAN). On the homology of the M. marsupialis and the M. 
pyramidalis in mammals. 1119. 
W AALS (VAN DER) (The cohesion forces in the theory of). 943. 
Wapiak, Java (The proto Australian fossil man of). 1013. 
WATERMAN (H. I.) and J. Groot. The influence of different substances 
on the decomposition of monoses by an alkali and on the inversion 
of cane sugar by hydrochloric acid. 149. 
WAVELENGTH (Extinction by a blackened photographic plate as function of) 
quantity of silver and size of the grains. 848. 
WEBER (MAX) and G. A. F. MOLENGRAAFF. On the relation between 
the pleistocene glacial period and the origin of the Sunda sea (Java- 
and South China-sea), and its influence on the distribution of coralreefs 
and on the land- and freshwater fauna. 395. 
