About the middle of May the 307th Infantry Regiment of the American Army (77th Division) was attached to the 42nd for instruction and training, and for three weeks the Americans took part in all schemes arranged for the Division. The training was divided into three stages. In the first, the U.S. platoons were attached to companies of the 42nd; in the second, U.S. companies were attached to battalions; and later the U.S. battalions formed the fourth battalions of infantry brigades. The U.S. Pioneer Section was attached to the Divisional R.E. The Americans were naturally rather green, and their conception of warfare was perhaps more crude than they had imagined, but they proved quick and willing learners, although it was alleged that in one company the platoon-sergeants had to give instruction in sixteen different languages. They contributed nobly to entertainments, and in return for tuition in football, boxing and warfare, they taught the Division to jazz, and a considerable portion of it, including its Commander, to play baseball. Officers and men of the two armies mixed together with cordiality, good-fellowship and mutual respect, these sentiments being further stimulated by a really good dinner, followed by a well-organized entertainment, given to the attached Americans by Colonel Clare and the 5th East Lancashires in the middle of a wood near Pas. When, on June 3, the Americans were ordered to entrain for the south, it was a common disappointment that they would not have the opportunity of fighting side by side with the men with whom they had helped to train.