Vol. 6, 1920 
GENETICS: C. C. LITTLE 
and the United States white. There is, however, no significant differ- 
ence between the European "hybrid" and the United States white. This 
shows that in the data studied, the United States white ratio is essentially 
that of a hybrid race. 
TABLE 1 
MALES 
FEMALES 
RATIO 
(a) European Pure 
2807 
2689 
104.54 ± 
0 
97 
(b) European Hybrid 
677 
551 
122.86 =t 
2 
14 
(c) United States White 
994 
840 
118.33 ± 
1 
71 
(d) British W. I. Colored 
667 
618 
107.92 ± 
2 
65 
(e) United States Colored 
695 
723 
96.12 ± 
1 
76 
COMPARISON 
DIFFERENCE 
DIFFERENCE 
PROBABLE ERROR OF 
DIFFERENCE 
18.32 
± 2 
35 
7 . 8 Significant 
European Pure X U. S. White 
13.79 
± 1 
9 
7 . 2 Significant 
European Pure X B. W. I. Colored 
3.38 
± 2 
82 
1 . 2 Not significant 
European Pure X U. S. Colored 
8.42 
± 2 
0 
4.2 Significant 
European Hybrid X U. S. White 
4.53 
± 2 
74 
1 . 6 Not significant 
U. S. White X U. S. Colored 
22.21 
± 2 
45 
9 . 0 Significant 
B. W. I. Colored X U. S. Colored 
11.80 
± 3 
18 
3 . 7 Significant 
This behavior of the United States matings is not in the least surprising 
for the number of different racial stocks involved in the production of the 
parents of the offspring recorded is undoubtedly large. 
The British West Indies colored stock, while far from pure, is obviously 
more nearly so than the United States colored. This is true because of 
the fact that the United States colored in addition to including offspring 
whose grandparents were born in the United States, also admits the chance 
that part of the grandparents may have been themselves British West 
Indies stock, thus adding the hereditary variations of this stock to that 
of the United States colored stock. It is interesting to note that the 
ratio of the B. W. I. stock does not depart significantly from that of the 
European pure whites (see table 1). On the other hand, the United States 
colored differs significantly from both B. W. I. colored, and from European 
pure and United vStates whites. 
We may, therefore, class our matings into two main groups — the 
European pure and the B. W. I. colored, as being relatively "pure" and 
the European hybrid, United States white, and United States colored as 
being relatively "hybrid." 
Let us now examine the nature of the ratios when the progeny of primi- 
para are separated from other births. 
