662 



aiiollier rise in December and Jannaiy. I slionUI feel inclined to 

 explain tiiis niontiii}' difference in the following way: Beginning 

 with February 1 should like to regard the rapid atul regular rise 

 up to May as a reaction on the general climatological factor, tiie 

 influence of awakening nature, and not so much as an influence of 

 temperature, which seems to me in these mouths not capable of 

 doubling the frequency in May, con)pared to what it was in February. 

 I would then be inclined to see an influence of the temperature in 

 the fact that duiing the actual summer months the frequency remains 

 almost equal to what it was in Maj'. The rise of frequency in 

 December and January can |)erhaps be looked upon as the result 

 of the artificial higher temperatures to which the organism is subjected. 

 As has been mentioned in the beginning of this communication, 

 i have also been able to collect the data of 165 Jewesses, referring 

 to the age of the menarche. Naturally these almost entirely relate 

 to inhabitants of large towns. The following Table VII gives a 

 survey of the frequency, according to the age of the individual, in 

 absolute tignres and in relative percentages, which are made clear 

 by curve A in fig. 2. 



TABLE VII. 



The following remark must be made with regard to this Table. 

 In the 3 cases arranged under the JO"' year, the first menses 

 appeared in the second half of this age (JO years, 7 months; 10 

 years, 9 months; and 10 years, Jl months). The variation curve of 

 the menarche begins, therefore, in the Jewish girls at the same age 

 as in the non-Jewish. It is true there was one case in which the 

 menarche already began at the age of 9 years, but this case (9 years 

 1 month), is separated by an interval of a year and a half from 

 the following, and must therefore be regarded as a sign of abnormal 

 precocity. For the Jewish race also, therefore, the middle of the 

 10''' year counts as the thresiiold of sexual maturity. 1 would again 



