366 DAVENPORT— EFFECTS OF RACE INTERMINGLING. 



Take the case of the Leghorn hen. Its function is to lay eggs all 

 the year through and never to waste time in becoming broody. The 

 brooding instinct is, indeed, absent ; and for egg farms and those in 

 which incubators are used such birds are the best type. The Brahma 

 fowl, on the other hand, is only a fair layer ; it becomes broody two 

 or three times a year and makes an excellent mother. It is well 

 adapted for farms which have no incubators or artificial brooders. 

 Now I have crossed these two races ; the progeny were intermediate 

 in size. The hens laid fairly well for a time and then became 

 broody and in time hatched some chicks. For a day or two they 

 mothered the chicks, and then began to roost at night in the trees 

 and in a few days began to lay again, while the chicks perished at 

 night of cold and neglect. The hybrid was a failure both as egg 

 layer and as a brooder of chicks. The instincts and functions of the 

 hybrids were not harmoniously adjusted to each other. 



Turning to man, we have races of large tall men, like the Scotch, 

 which are long-lived and whose internal organs are well adapted to 

 care for the large frames. In the South Italians, on the other hand, 

 we have small short bodies, but these, too, have well adjusted 

 viscera. But the hybrids of these or similar two races may be 

 expected to yield, in the second generation, besides the parental types 

 also children with large frame and inadecjuate viscera — children of 

 whom it is said every inch over 5' 10" is an inch of danger; chil- 

 dren of insufficient circulation. On the other hand, there may 

 appear children of short stature with too large circulatory appa- 

 ratus. Despite the great capacity that the body has for self adjust- 

 ment it fails to overcome the bad hereditary combinations. 



Again it seems probable, as dentists with whom I have spoken on 

 the subject agree, that many cases of overcrowding or wide separa- 

 tion of teeth are due to a lack of harmony between size of jaw and 

 size of teeth — probably due to a union of a large-jawed, large- 

 toothed race and a small- jawed, small-toothed race. Nothing is 

 more striking than the regular dental arcades commonly seen in the 

 skulls of inbred native races and the irregular dentations of many 

 children of the tremendously hybridized American. 



Not only physical but also mental and temperamental incompati- 

 bilities may be a consequence of hybridization. For example, one 



