Anthropology. — "7'/<e Menarche in Dtiic/i Woi)ie7i a7i(l its preci- 

 pitated appearance in the youngest generation" . By Prof. L. Bolk. 



(Communicated at the meeting of September 29, 1923). 



Witli llie aid of several physicians I have collected a number of 

 data with regard to the menarche in Dutch women, ahout which 

 nothing was known so far. In collecting these data the greatest 

 accuracy has l)een observed and in this communication we iiave 

 only made use of the cases, in which not only the year, but also 

 the month of the first menstrnation has been noted. Besides this the 

 colour of hair and eyes of the various subjects had been stated, as 

 I also wished to ascertain through (his examination, whether the 

 degree of pigmentation is of influence in the commencement of 

 sexual maturity in the young girl. 



Although it is not easy to obtain accurate data, I have succeeded 

 in collecting 1800 reports of non-Jewish women as well as 165 of 

 Jewesses. 



Oil working out this material, several unexpected and surprising 

 results came to light, which 1 will relate in succession, leaving the 

 data obtained from the Jewesses until the end. 



The first question which could be answered with the aid of these 

 reports concerned the age at which the menarche appears in Dutcii 



TABLE I. 



