"You would be surprised at the number of people in these parts who nearly are half people and half camel," the Sergeant remarked. "As one rides a camel across the rocky roadsteads of the desert, the fierce repeated wallops between the humph of the camel and the human organ pressed into it with promiscuous propinquity causes agitation of the little shining adams comprehending them both, and it is inevitable that mollycules of one should change places with mollycules of the other. That camel's humph is over seventy percent nates and there is very little hope of ever getting his number below fifty again."
"Not Bactrian but Buttrian," said Joe.
UPDATE: I for one prefer not to speculate about the molecular-interchanging activities that resulted in Half Man Half Biscuit.