Pliny's work frequently reflects Rome's imperial expansion, which brought new and exciting things to the capital: exotic eastern spices, strange animals to be put on display or herded into the arena, even the alleged phoenix sent to the emperor Claudius in AD 47 – although, as Pliny admits, this was generally acknowledged to be a fake. Pliny repeated Aristotle's maxim that Africa was always producing something new. Nature's variety and versatility were claimed to be infinite: "When I have observed nature she has always induced me to deem no statement about her incredible." This led Pliny to recount rumours of strange peoples on the edges of the world. These monstrous races – the Cynocephali or Dog-Heads, the Sciapodae, whose single foot could act as a sunshade, the mouthless Astomi, who lived on scents – were not strictly new. They had been mentioned in the fifth century BC by Greek historian Herodotus (whose history was a broad mixture of myths, legends, and facts), but Pliny made them better known.