( 397 ) 



has no influence on the result, as would be the case if fresh solutions 

 of NaCl were taken each time. 



A last remark concerns the applicability of the method. It cannot 

 be used so generally as the freezing point method : It cannot be 

 applied with gall since this fluid contains substances causing haemolysis ; 

 it also fails for urine, since this fluid contaius a relatively large 

 quantity of urea which contributes considerably to the osmotic 

 pressure but has no iufluence on the volume of the blood corpuscles. 



For a number of other fluids, as blood serum, lymph, cerebro- 

 spinal fluid, saliva, lachrymal fluid, etc., the method can be success- 

 fully applied. It does not matter whether the fluids are coloured, for 

 the determination only depends on the volume occupied in the fluid 

 by the blood coi-puscles. 



Zoology. — "On the primordial cranium of Tarsius spectrimi\ 

 By Prof. Dr. Eugen Fischer of Freiburg i. B. (Preliminary 

 paper). Communicated by Prof. A. A. W. Hubrecht. 



An investigation of the primordial cranium of Tarsius spectrum 

 seemed particularly interestiug to me as it might till up a gap I had 

 found when making a comparative study of the cartilaginous skull 

 of apes and man on one hand, and of lower mammals (the mole) 

 on the other ^). So I was exceedingly happy when Prof. Hubrecht, 



1) Fischer E. Das Piimordialci-aniuin von Talpa curopae. Anat. Hefte Bd. 17, 

 1901 and: zur Entwicklungsgescliichte des AfTenscliadels. Zeitschr. f. Morph. und 

 Antbrop. Bd. 5, 1903. 



