Die Preussische expedition nach Ost-Asien. bd.2. Berlin :Königlichen geheimen ober-hofbuchdruckerei (R. v. Decker),1867-1876. biodiversitylibrary.org/page/14040776 Helix snails shoot "love darts" en.wikipedia.org/wiki/Love_dart at potential mates. C Helix brasiliana in #bhlib (fig. 1) biodiversitylibrary.org/page/14040776