In "Origin of Species," the object of intense research for nearly a century and a half, Charles Darwin refers to a "Mr. Collins" as if he were a famous cattle breeder. In fact, there is no mention of a famous cattle breeder called Collins anywhere else in the literature, although there is a suitable candidate for this description by the name of "Colling." Darwin's reference to Mr. Collins is probably an error. This paper will attempt to establish the identity of (...) the real Mr. Collins, and also to suggest why the mistake has gone unnoticed for so long. (shrink)