Vomeronasal organ. The vomeronasal organ (VNO), or the Jacobson's organ, is an auxiliary olfactory sense organ that is found in many animals. It lies close to the vomer and nasal bones. It was discovered by Frederik Ruysch prior to 1732 and later by Ludwig Jacobson in 1813. This organ is the sense organ involved in the flehmen response in mammals.
In the 19th century, the postal system continued to grow. The Post Office Department, which had been founded to oversee the Postal Service, developed new services and established new post routes. As the United States grew dramatically between 1789 and 1861, when the Civil War broke out, its population also increased.
History of United States postage rates. Seal of the former U.S. Post Office Department (1792â1971), predecessor to the USPS. Initial United States postage rates were set by Congress as part of the Postal Service Act signed into law by President George Washington on February 20, 1792. The postal rate varied according to distance zone, the distance a letter was to be carried from the post office where it entered the mail to its final destination. Rates were adopted in 1847 for mail to or from the Pacific Coast and in 1848 for mail sent from one place in the west to another place in the west. There were double and trip