Here is something from Wikipedia. I'm not sure if they are the same bird as the Cornish X, that grows so fast, that I've read about on this forum.
Edited by goldnchocolate - 7/19/09 at 6:07pm
Cornish game hen
From Wikipedia, the free encyclopedia
A Cornish game hen, also sometimes called a Cornish hen, poussin, Rock Cornish hen, or simply Rock Cornish, is a young chicken sold whole. Despite the name, it is not a game bird, but actually a typical chicken that is slaughtered at a young age and therefore is smaller in size. Though the bird is called a "hen," it can be either male or female.
Most sources credit Alphonsine and Jacques Makowsky of Connecticut for developing the small bird in the mid-1950s. A Saturday Evening Post article from July 1955 credited Mrs. Makowsky with coming up with the idea to breed the Cornish game chicken, a small bird with short legs and a plump, round breast that she had discovered in a book. The Makowskys began cross-breeding the Cornish game cocks with various chickens and game birds, including a White Plymouth Rock hen and a Malayn fighting cock, to develop the Rock Cornish game hen -- a succulent bird with all-white meat. Their intent was similar, to breed a small chicken with mostly white meat suitable for a single serving.
In addition to commanding a higher price, the game hens have a shorter growing span, 28 to 30 days as opposed to 42 or more for regular chicken. Two-thirds of Cornish game hens sold in the United States come from Tyson Foods, Inc.
The U.S. Department of Agriculture describes the Rock Cornish game hen or Cornish game hen as a young immature chicken (usually 5 to 6 weeks of age), weighing not more than 2 pounds ready-to-cook weight, which was prepared from a Cornish chicken or the progeny of a Cornish chicken crossed with another breed of chicken.