In collaboration with the Thuringian University and State Library book scanning service in Jena, one of our students scanned all three volumes of Haeckels monograph on calcisponges. It is likely that Ernst Haeckel himself donated this particular three volumes to our library. All volumes are now available through the Digital Library Thuringia (dbt - Digitale Bibliothek Thüringen).

Please feel free to download PDF copies from the dbt server:

•  Haeckel, E (1872) Die Kalkschwämme Bd. 1: Biologie der Kalkschwämme : Genereller Theil ; (Caleispongien oder Grantien) (32 MB)
• Haeckel, E (1872) Die Kalkschwämme Bd. 2: System der Kalkschwämme : Specieller Theil ; (Caleispongien oder Grantien) (31 MB)
  
• Haeckel, E (1872) Die Kalkschwämme Bd. 3: Atlas der Kalkschwämme : Illustrativer Theil ; (Calcispongien oder Grantien) ; 60 Tafeln Abbildungen nebst Erklärung (11 MB)