Josiah Gregg and Dr. George Engelmann.

The article presents letters which illustrate the relationship between merchant Josiah Gregg and botanist George Engelmann, including letters from Gregg to Engelmann regarding Mexican plants as well as murders and executions occurring during Gregg's expedition to Mexico and a letter to Engelmann by Josiah Gregg's brother John Gregg regarding Josiah Gregg's death.