 The working Jack Russell Terrier is still very much alive and is as common as ever, presenting itself in an astounding variety of coats (smooth, broken and wire coated or rough), sizes (10 inches to 15 inches tall with most working dogs sized 10 to 13 inches tall), and coat colors (from pure white to 49 percent colored with tan and black markings).There is even a new type of working Jack Russell – the “Plummer Terrier” first created by Brian Plummer in the 1970s and breeding true since the mid-1980s.What of all of the other Kennel Club breeds of terriers?