In 1907-08, with Hugo Merton, he performed scientific research in the Aru and Kei Islands, and in 1911-12, with Fritz Sarasin, he visited New Caledonia and the Loyalty Islands. As a result of the latter expedition, he published with Sarasin a major work titled, Nova Caledonia. Forschungen in Neu-Caledonien und auf den Loyalty-Inseln. Recherches scientifiques en Nouvelle-Calédonie et aux iles Loyalty. During his career, he was the author of 35 papers on herpetological subjects.
