[2] In 1900, he won the University of Graz's "Unger Prize" for a work on the anatomy of the roots of exotic orchids.
This led him to study the arthropod fauna found in caves of the Trieste region, especially blind insects.
[3] After presenting his results at the International Congress of Zoology in Graz, he became known in larger circles and started many scientific cooperations.
In his study on the body louse, he proved that the bacteria Rickettsia prowazekii, known to cause epidemic typhus, is transmitted by the insect.
He also planned the construction of an aquarium in Trieste, which included many coral fish from Red Sea and that was opened in 1933.