Musings on the English language

When did the word fruit cease to be plural?

I was reading an review of "Eating the Sun" by Oliver Morton, in which he is quoted as saying, "...the source of energy that gives the stardust life is as close as the summer which ripened the fruits on our table." This British gentleman has a degree in history and philosophy of science. (I Googled him) He went to Cambridge, fer crying out loud! Mr. Morton isn't the only culprit, just the one fingered most recently.

Another pet peeve of mine was the incorrect usage of "negative reinforcement". What most people mean, when using that phrase, is "positive punishment". But a friend of mine in the field told me to give up; that genie was long gone out of the bottle.

Of course, that is how language evolves. For instance, the verb "to Google", that's a new one. Oh, and "to friend", i.e. "I friended Pastor Rob on Facebook yesterday."

But, really? Fruits?!