128 



Scientific Proceedings (ioo). 



It is believed that a close approximation to experimental con- 

 ditions exists at the large lying-in hospitals. Here the patients 

 are observed carefully, the sex of every offspring, including still 

 births recorded, and the environmental conditions are for at least 

 the period of confinement, as nearly equal as possible. The 

 nationality of the parents of every child is recorded and the data 

 thus obtained although not including nearly as large a number of 

 cases as that of the Pearls, may, I believe, properly be considered 

 accurate. During the past few months therefore, a study has 

 been made of the records at the Sloane Lying-in Hospital, New- 

 York City. For this opportunity thanks are due to the staff 

 and trustees of the hospital. The types of matings studied are 

 those within each of the following races: English, Irish, Scotch, 

 Italian, Russian, Greek, Austrian and German, and matings of 

 all possible first generation types between these races. Matings 

 of this latter category which produce racial hybrids are con- 

 trasted with matings within the pure races in the following table: 



Table II. 





Total 

 Ind. 



Males. 



Fe- 

 males. 



Ratio. 



Difference. 



Difference 

 P. E. 



Pure stocks 



Hybrids 



5.753 

 1.305 



2,964 

 716 



2.789 

 589 



106.27 db -91 

 I2i.56i2.06 



i5.29i2.26 



6.76 



It will be observed that although the numbers are smaller, 

 the significance of the difference between the pure and hybrid 

 stock is distinct. It will further be noted that both ratios are 

 considerably higher than either of the Pearls. 



In considering the probable effects upon their data of the 

 missing still births the Pearls recognize the following three possi- 

 bilities. 



(a) That still births are distributed pro rata in pure and 

 hybrid matings. 



(b) That still births are more frequent in pure matings than 

 in hybrid. 



(c) That still births are more frequent in cross matings than 

 in pure matings. 



They recognize the fact that if either condition (a) or (c) 



