In contrast to the metric system, English measure is a jumble of idiosyncratic ratios and history-bound names.

In a similar vein, we have an equally eclectic set of collectives-idiomatic:

Barrel of monkeys
Bowl of cherries
Can of worms
Pint of pickled peppers
Nest -- mare's, hornets', wasps', rat's
Ship of fools...

One asks, why do each of these things come in those particular units? Are there any more examples?

I don't know why these come in units, and I don't really know how to research it. Perhaps some of our linguists know? In the meantime, I will look them up individually.

I thought it was "peck of pickled peppers."

Of course, Robert Frost talks about a "Peck of Gold:"

Dust always blowing about the town,
Except when sea-fog laid it down,
And I was one of the children told
Some of the blowing dust was gold.

All the dust the wind blew high
Appeared like god in the sunset sky,
But I was one of the children told
Some of the dust was really gold.

Such was life in the Golden Gate:
Gold dusted all we drank and ate,
And I was one of the children told,
'We all must eat our peck of gold.'

This message has been edited. Last edited by: Kalleh,

Well, you can start with groups of animals, a murder of crows, a pride of lions, an exhaltation of larks. In fact, the last is the title of a book by James Lipton of "Inside the Actors Studio". I've been meaning to buy this book for some time, and the amazon page is here The first review describes well the different ways these things are created.

There are many of these terms in English, which must reflect the love of English speakers to create new idioms. Bowl of cherries obviously comes from the fact that cherries are served in a bowl. Can of worms is an idiom meaning bad thing. You open up your can and discover it is full of worms. Peck of pickled peppers is purely for alliterative purposes for the tongue twister. I don't see why you have the nest example. Ship of fools is probably a literary reference to somewhere. I can't seem to track down barrel of monkeys, but I'm confident an explanation will present itself.

A peck is one of the old Imperial dry measures used since at least the 14th century, although they are very rarely used nowadays. 2 gallons = 1 peck. The gallon was mentioned in Piers Plowman by William Langland (1342).

There's the well-known tongue twister - "Peter Piper picked a peck of pickled peppers" already mentioned, you can have "a peck of trouble", and you're supposed "to eat a peck of dirt before you die".

The instant I read kalleh's correction of "peck," I recalled the rhyme. And arnie gives a nice background.

My goal here is not to re-create the fine work done by Lipton in "An Exaltation of Larks" but ask a less serious question -- wheredid we get such silly idiomatic collectives.

It sprang in fact from a discussion on mandarin oranges, which do not come from an orchard like proper oranges, but rather from a can...