Warbler Variations and the Origin of a Species
The mule is in many ways an admirable creature. It’s tough and adaptable. It has a mind of its own, but it’s open to negotiation. The US Army has rediscovered the virtues of mules as pack animal in inhospitable terrain like most of Afghanistan. The one thing a mule can’t do, of course, is reproduce its own kind. The offspring of a male horse and a female donkey, it’s the archetypal sterile hybrid. -more-