Please answer the following question: Given the following context:  By October 9, Cos had taken over San Antonio de Béxar. Stephen F. Austin sent an advance scout troop of 90 men under James Bowie and James Fannin to observe the Mexican forces. While taking refuge at Mission Concepción on October 28, they repelled an attack by 275 Mexicans under Domingo Ugartechea during the battle. Austin continued to send troops to Béxar. Bowie was ordered on November 26 to attack a Mexican supply train alleged to be carrying a payroll. The resulting skirmish became known as the Grass Fight, after it was discovered that the only cargo was grass to feed the horses. When Austin was selected to join Branch T. Archer and William H. Wharton on a diplomatic mission to seek international recognition and support, Edward Burleson was named as commander. On December 5, James C. Neill began distracting Cos by firing artillery directly at the Alamo, while Benjamin Milam and Frank W. Johnson led several hundred volunteers in a surprise attack.  The fighting at the Siege of Béxar continued until December 9 when Cos sent word he wanted to surrender. Cos and his men were sent back to Mexico, but would later unite with Santa Anna's forces.Approximately 300 of the Texian garrison at Béxar departed on December 30 to join Frank W. Johnson and James Grant on the Matamoros Expedition, in a planned attack to seize the port for its financial resources. Proponents of this campaign were hoping Mexican Federalists would oust Santa Anna and restore the 1824 constitution. When Sesma crossed the Rio Grande, residents of the Gulf Coast began fleeing the area in January 1836. Santa Anna ordered General José de Urrea on February 16 to secure the Gulf Coast. About 160 miles (260 km) north of Matamoros at San Patricio, Urrea's troops ambushed Johnson and members of the expedition on February 27 at the Battle of San Patricio. Sixteen Texians were killed, six escaped, and 21 were taken prisoner. Urrea's troops then turned southwest by some 26 miles (42 km) to Agua Dulce Creek and on March 2 attacked a group of the expedition...  answer the following question:  What was on the Mexican supply train Bowie attacked on November 26?
A:
grass