"As i have said, these little house dogs are of all shapes, varying as to size, and many colors. As to these points the Mexican cares little. 

His one indication of the purity of the breeding is the orifice in the center of the skull - the great peculiarity of this breed and found in no other."

The CHIHUAHUA dog , by JAMES WATSON

(Country Life in America, March, 1914)