At the lower temperatures the experimental values of B appear 
to lie between the curve for the quadruplets and that for the 
doublets*). This is (comp. $ 2) also the case with the curve which 
follows from the assumption CLacsits—Bertue.or (dotted curve in 
Fig. 1). For ascending values of 8/g. at equal 7/r, __, the 
order of succession is: doublets, CLavstus—Bertxetor, hydrogen, 
quadruplets. 
§ 4. The Borre-point. For the ratio of the temperature Ta, of 
the BoyLe-point (at which 4—0), to that of the inversion point for 
the JouLe—KeE vin-effect at small densities we obtain: 
TB [Tia e=0 
ay and by, independent of temp. 0.5 
quadruplets 0.539 
hydrogen *) 0.552 
CLatsius—BERTHELOT 0.577 
doublets 0.592 
In these figures the same order of succession appears as that 
mentioned in § 3. 
Anatomy. — “The jissura simialis in embryos of semnopithect’. 
By Dr. D. J. Httsnorr Por. (Communicated by Prof. 
C. WINKLER.) 
(Communicated in the meeting of February 26, 1916). 
The interpretation of what is meant by the ape-fissure has often 
changed in the course of years, however, the sulci interparietalis *) 
(J+ e), parieto-occipitalis lateralis (m + m’) and parieto-occipitalis 
medialis (77), have always played an important part in it. 
Frarrav and JacoBson *) thought the apefissure (fissura simialis) 
to be identical with the suleus parieto-occipitalis lateralis (m —+ m’) 
and called it the most characteristic in the ape brain. It should 
1) In the series of values of B given by Kamertincn Onnes and Braak that for 
t = — 139.859 (f(inv) = 0.685) forms the only exception to this rule. 
2) TB = 107.4 according to KAMERLINGH ONNEs and BRAAK, Comm. NO, 100a § 22. 
Tinv (p=0) = 194.5 according to Suppl. N°. 39a § 5. 
8) In the nomenclature I followed, after KoHLBRUGGE and Bork, the one used 
by KiicKENTHAL and ZIEHEN. In KOHLBRUGGE’s reference “Die Variationen” etc. 
Zeitschrift fiir Morph. u. Anthr. Bd. VJ, 1903, the whole nemenclature is given. 
4) Frarau u. JacoBson. Handbuch der Anatomie und vergl. Anat. des Centr. 
Nervensyst. der Säugethiere. Berlin 1899. 
101 
Proceedings Royal Acad. Amsterdam. Vol. XVIII. 
