April 12, 1895.] 



SCIENCE. 



403 



It appears from these four tables that 

 first-born children exceed later-born chil- • 

 dren in stature as well as in weight ; that 

 this difference prevails from the sixth j'ear 

 until the adult state in females, and from 

 the sixth year to the fifteenth in males. The 

 material is not suflicientl_y extensive to show 

 if the same is true of the adult males. Al- 

 though the ditference is not large, it occurs 

 with such regularity that there can be no 

 doubt as to the reality of the phenomenon. 

 The available material is not very extensive, 

 and the subdivision into five classes makes 

 each class so small that the existing irregu- 

 larities are not surprising. A preliminary 

 investigation of the Toronto material is 

 entirely in accord with the results dei-ived 



from the Oakland material, the difference in 

 favor of the first-born being, if anything, 

 more marked. 



We are, therefore, justified in grouping 

 the measurements into two classes : first- 

 born indi\dduals and later-born individuals. 

 This increases the difference of stature of 

 the two groups to 10 mm. in girls, to 7 mm. 

 in boys, and the difierences of weight to 1.6 

 pounds in girls and to 1.2 pounds in boys. 

 The tables seem to indicate that second- 

 born children exceed somewhat later-born 

 children in stature and weight, but the ma- 

 terial is not sufficiently extensive to allow 

 us to make a safe deduction on this ques- 

 tion. 



It would seem likely that the greater 



