The Determination of Sex 367 
localities from which he obtained the eggs, with the following 
results : — 
Prop. 1n NATURE OBTAINED ARTIFICI ALLY 
Male Female Male Female 
Utrecht 13.2 100 18.1 100 
Bonn 36.6 100 35-7 roo 
Konigsberg 467 100 48.5 100 
The meaning of the enormous difference is by no means clear. 
Lenhossek has suggested that if the Utrecht egg were to be fer- 
tilized with sperm from the Kénigsberg race, and vice versa, 
interesting results in regard to whether the egg or the spermato- 
zoon determines the sex might be obtained. 
Geddes and Thomson state that in fishes the females are usu- 
ally more numerous than the males, never less so, except in 
anglers and catfish. They give the following data: — 
FEMALE Mae 
Flounder a r : : : é 2 P I to I 
Roughead . : ; ‘ ‘ : : 2 12 to I 
Cod. . 3 = ‘ . ‘ a : 3 to 2 
Gurnard ‘ : j ; : : ‘ é 9 to 2 
There is a further point of some importance in regard to man, 
namely, the proportion of males and females that occur in abor- 
tive births and of still-born infants. The statistics show that a 
much larger number of these are males. Thus Rauber found 
the proportion for 57 embryos was 159 males to 100 females. 
Lenhossek examined 156 embryos (between the third and sixth 
month), and found the proportion to be 160 males and 100 
females. 
For still-born infants, fully formed, but not alive, the follow- 
ing figures have been given: — 
