49 8 B 



TRANSMISSION 



The table given on page 480 and the deductions therefrom are fully con- 

 firmed by recent work done by Dr. H. L. Rietz in cooperation with the writer, 

 as shown in tabular form on the preceding page. 



In this work are included all the cows (608 in number) making 1 1 pounds or 

 more of butter fat per week and descended from dams making 1 1 pounds or 

 more, as recorded in the Holstein-Friesian Advanced Register. 



From this study the deductions are the same as those established by Gal- 

 ton's table of statures, the confirmation being the more significant because the 

 characters are widely separated, one being in man and the other in animals, 

 leading to the conclusion that these deductions are of the nature of general 

 laws of heredity, as follows : 



1 . Dams of the same class may and do produce a great variety of descend- 

 ants. Thus the ninety-four 1 4-pound dams (row e) produced all classes of cows 

 from 1 1 -pound up to 24-pound, although the greatest number were 1 5-pound 

 and 1 6-pound cows. 



2. Cows of any given class may be produced by a great variety of dams. 

 Thus the ninety-three 1 6-pound cows (column 7) were produced by all sorts of 

 dams ranging from n -pound up to 23-pound, all of which has but one mean- 

 ing, namely, that no direct and fixed relation exists between the offspring and 

 its immediate or personal parent. 



3. The average of all the off spring (15. 31 6) is slightly below the average of 

 the dams (15.368). 



4. For all dams below the average of dams (15.368) the average of the off- 

 spring is above that of their dams; but for dams above the average, the 

 offspring is in general inferior to the parentage. 



5. Dams of all classes produced some offspring that were inferior to them- 

 selves and others that were superior, and this is as true of dams below the 

 average as well as of dams above the average. 



6. Many exceptional cows were produced by average dams and below, but 

 the greatest proportion of exceptional cows was produced by superior dams. 



In comparing this table with Galton's table of statures it must be borne in 

 mind that while Galton's table of statures involved little or no selection, we are 

 here dealing with a highly selected population descended from a single (female) 

 parent, but mated with exceptional sires, which, on the whole, are superior to 

 the dams. It must also be borne in mind that we do not have here the entire 

 population, all below 1 1 pounds having been discarded ; hence the fullness of 

 the table at the upper left-hand corner. 



