While teaching zoology at the University of Pennsylvania and in the Medical Department, Leidy constructed teaching charts for many aspects of his lectures. Some were drawn and signed by Leidy, some copied by him from textbook figures and still others were copied from texts by students under Leidy's supervision. These were stored in a great chest and used for years as teaching devices by his successors at the University. Because they are currently little used, the department agreed to deposit part of the collection at the Academy. Those chosen are signed by Joseph Leidy, or bear his handwritten legends and notes.