An author known to adult readers for his Roving South -- Key to Japan etc. draws on authentic experience for this adventure story of the Amazon jungle. His heroes are brothers, Hal and Roger Hunt, who have gone with their father to bring creatures of the jungle back for the zoo. On a dangerous trip down the Amazon, a rival gang threatens them, the father is forced to return, leaving the boys to carry on. The story of how they met the challenge is a good one, and painlessly the reader acquires a lot of information about jungle life. Definitely for the market that likes true exploration adventure.