KONINKLIJKE AKADEMIE VAN WETENSCHAITEN 

 TE AMSTERDAM. 



PROCEEDINGS OF THE MEETING 

 of Friday April 27, 1906. 



(Translated from: Verslag van de gewone vergadering der Wis- en Natuurkundige 

 Afdeeling van Zaterdag 31 Maart 190G, Dl. XIV). 



L. Bolk: "On the relation between the teeth - form ulas of the platynhine and eatanhiue 

 Primates", p. 781. 



F. M. Jaeger: "A simple geometrical deduction of the relations existing between known and 

 unknown quantities, mentioned in the method of Voigt for determining the conductibility of 

 heat in crystals". (Communicated by Prof. P. Zeemas), p. 793. 



W. BfKCK: '-On plants which in the natural state have the character of eversportin}.; varieties 

 in the sense of the mutation theory". (Communicated by Prof. J. W. Moll), p. 798. 



H. Stkaiil: •■The uterus of Erinaceus europaeus L. after parturition". (Communicated by 

 Prof. A. A. W. Ill brecht), p. 812. 



P. Zeemax: "Magnetic resolution of spectral lines and magnetic force", (1st partj p. 8U. 

 (With one plate). 



Jax de Vkies: "Some properties of pencils of algebraic curves", p. 817. 



H. ZwAAKDEMAiiER: "On the strength of the reflex-stimuli as weak as possible", p. 821. 



Anatomy. — "On the relation between the teeth-formulas of the 

 platyrrhine and catarrhine Primates". (^Communicated by 

 Prof. L. BoLK). 



(Communicated iu the meeting of March 31, 1906). 



Among the anatomical characteristics by which the Primates of 

 the New-World — the platyrrhine apes — are distinguished from 

 those of the Old- World — the catarrhine apes and man — tJie com- 

 position of the set of teeth takes a first place. They are charac- 

 terized because they possess in the upper and lower jaw one milk- 

 molar with premolar, which replaces this, more than the latter. 



In simplified writing the set of teeth of catarrhine Primates may 

 be rendered by the following formula: 



55 

 Proceedings Royal Acad. Amsterdam. Vol. VIII. 



