144 C. M. Jackson. 



bered that the age of the fetuses observed wasi determined in some 

 cases by their length, the same rule being used for, both sexes. Since 

 the body length of the male at term averages greater than that of the 

 female, the same thing is probably true for the fetus, at least in the 

 later months. If allowance were made for this in grouping the 

 fetuses by months, the difference in body weight between male and 

 female would be even more pronounced. 



In mosit of the viscera observed, on the other, hand, the organs are, 

 as a rule, relatively heavier in the female.^ This is the case with 

 the brain, heart, liver, spleen and suprarenal glands ; while the thy- 

 mus, lungs and kidneys are usually relatively heavier in the male. 

 For the other organs, insufficient data are available. 



The brain averages larger in the female in every month, excepting 

 the 4th, 5th and 8th. Wo data are available for the female in the 

 9th month, however; and none for the male in the 2d. So that, 

 after all, the preponderance of relative weight in favor of the female 

 is but slight, and perhaps without significance. 



In the thymus, the relative size averages greater in the male for 

 every month recorded, except the 10th. Here the averages are equal 

 for those born alive, but slightly larger for the female in the still- 

 born. 



The heart averages relatively larger in the male for the 4th, 8th 

 and 9th months ; equal in male and female for the 7th ; and is larger 

 in the female for the remaining months. Here also the significance 

 of the difference is questionable, though well marked in the newborn. 



The lungs, both right and left, average relatively larger in the male, 

 excepting in the 3d month (2 cases only), 9th month (no data for 

 female), and 10th month. In the 10th month, the averages are 

 nearly equal in the still-born, but are decidedly larger for the female 

 in the live-born. 



The liver averages relatively larger in the female for every month 

 from the 3d onward. The only exception is the 9th month, in 

 which no data are available for the female. 



*This general conclusion was reached by Loisel (27) from a study of 

 Legou's cases. The additional data now available do not confirm most of 

 his conclusions, however. 



