Iowa State University Veterinarian Records, RS 22/6/0/9, University Archives, Special Collections Department, Iowa State University, http://www.add.lib.iastate.edu/spcl/arch/rgrp/22-6-0-9.html
In a previous issue the cryptorchidism of the horse was discussed, with its probable mode of inheritance. The same anomaly is known in other animal species as well, being perhaps most frequent in the horse, with swine, cattle and sheep following in that order.
Carman, Grant M.
"Cryptorchidism In Swine,"
Iowa State University Veterinarian: Vol. 14
, Article 4.
Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol14/iss1/4