I had bought two male chimps from a primate colony in Holland. They lived next to each other in separate cages for several months before I used one as a [heart] donor. When we put him to sleep in his… — Christiaan Barnard Copy Share Image
Because men, compared to male chimps, have such relatively small testicles (large testicles indicate a species where many males mate, one after the other, with the same female), we might guess that promiscuous societies were uncommon in the immediate human… — Carl Sagan Copy Share Image
![“I had bought two male chimps from a primate colony in Holland. They lived next to each other in separate cages for several months before I used one as a [heart] donor. When we put him to sleep in his cage in preparation for the operation, he chattered and cried incessantly. We attached no…” quote by Christiaan Barnard](https://sms4smile.com/quotes/img-quotes/3b9/christiaan-barnard-39607_animal_i-had-bought-two-male-chimps-from-a-prim_126559.jpg)
