The great multitude of different breeds of the dog and the vast
differences in their size, points, and general appearance are facts
which make it difficult to believe that they could have had a common
ancestry. One thinks of the difference between the Mastiff and the
Japanese Spaniel, the Deerhound and the fashionable Pomeranian, the
St. Bernard and the Miniature Black and Tan Terrier, and is perplexed
in contemplating the possibility of their having descended from a
common progenitor.