Often, as in the case of the orange, the rind even contains a bitter, nauseous, or pungent juice, while at times, as in the pine-apple, the prickly pear, the sweet-sop, and the cherimoyer, the entire fruit is covered with sharp projections, stinging hairs, or knobby protuberances, on purpose to warn off the unauthorised depredator.    From Wordnik.com.  [Falling in Love With Other Essays on More Exact Branches of Science] Reference