of the Sexes among the Todas. 



483 



surprising. The supposition of $ infanticide, by accounting for the 

 great disproportion in the numbers of the sexes, brings the Todas 

 into harmony with what is known of the rest of mankind, whilst 

 it receives strong support from the following considerations. 



The genealogical system of registration adopted by Dr Rivers 

 has enabled me to estimate the proportion of the sexes and the 

 average fertility for several successive generations, and this inde- 

 pendently for both the Tartharol and Teivaliol Todas. The two 

 tribes have each been divided into four groups A — D, representing 

 approximately four generations. These are : — 



A. Families where the eldest child would be now (1903) over 90. 



B. „ „ „ „ „ between 60 and 90. 



C. „ „ „ „ „ „ 30 and 60. 



D. „ „ „ „ „ „ and 30. 



The results are given in Table II. 

 Table II. 



Neglecting Group A, where paucity of numbers renders the 

 figures somewhat untrustworthy, the series B — D tell the same 

 story for both tribes. There has been a steady decrease in the 

 proportion of <fs accompanied by an equally steady diminution of 

 fertility. As it may be objected that the figures for Group D are 

 unnecessarily low owing to the presence of families not yet com- 

 plete, I have recalculated the average size of the family in this 

 group, omitting all families where the age of the youngest child 

 is below 10 years of age. When this was done 33 such Tartharol 

 families gave an average of 2*5 and 22 Teivaliol families an 

 average of 2'4. As these figures are practically identical with 

 the whole of Group D in each case, it seems permissible to con- 

 clude that the tendency to sterility is becoming checked at the 



32—2 



