Achille Forti (1878-1937) was an algologist of international renown who left a collection to the University of Padua on his death, comprising around 8,000 slides with sea water (marine and brackish), fresh water and fossil diatoms from around the world: some his own work, others by scholars and preparators like Peragallo, Tempère, Smith, Thun and Moller. The slides mostly contain specimens mounted both frontally and in profile.

There are also some 1,700 photographic plates held by the museum, connected mostly with Forti’s algal material. These are silver bromide gelatin plates of different sizes, the smallest measuring around 9×12 cm and the largest 30×40 cm. The biggest group, numerically, is made up of plates with images of diatoms, some of which coincide with his slides; others reproduce images of dried sargassums, preserved in his collection or present in collections held by other museums but, in some cases, coming from the same collection campaign. Finally, there is a group of plates depicting extremely heterogeneous subject matter — palaeontological finds, places, objects and people of his time.