sentences:  Kerr interrupted his medical studies to join an Argentinian expedition to study the natural history of the Pilcomayo River.On his return, he studied natural sciences at Christ's College, Cambridge, graduating with first class honours in 1896.The Argentinian expedition had ended with the loss of most of the collections, but after graduating he mounted an expedition to the Gran Chaco, bringing home a large collection of material related to the South American lungfish, "Lepidosiren paradoxa".