Monotremes: Ameisenigel und Schnabeltier, Holzschnitte, veröffentlicht im Jahre 1897 - Stock-Grafiken

Monotremes: 1) Short-beaked echidna (Tachyglossus aculeatus, or Echidna hystrix); 2) Underside of a female Short-beaked echidna with breast pouch; 3) Inside of the abdominal wall of a Short-beaked echidna with breast pouch and the mammary glands; 4) Platypus (Ornithorhynchus anatinus, or Ornithorhynchus paradoxus). In the background the den in cross section view. Wood engravings, published in 1897.