@misc{indiciae501fe8c2532e,
  title = {Principles of comparative physiology / Principles of comparative physiology. : [Supplementary material in Charles Darwin's copy] — Illustration, Page 68},
  year = {1854},
  url = {https://www.biodiversitylibrary.org/page/34067928},
  note = {Source identifier: page-34067928}
}