On the Origin of Species By Means of Natural Selection, or, the Preservation of Favored Races in the Struggle for Life. When on board H.M.S. ‘Beagle,’ as naturalist, I was much struck with certain facts in the distribution of the inhabitants of South America, and in the geological relations of the present to the past […]

Thirteen specimens of frogs collected in the summers of 1960 and 1961 in the Mexican states of Durango and Sinaloa represent a heretofore unnamed species. The specimens have been deposited in the Museum of Natural History of the University of Kansas (KU) and in the Museum of Michigan State University (MSU).

Field studies on hylid frogs in southern México and northern Central America have resulted in the collection of numerous specimens of _Ptychohyla_, a genus of hylid frogs heretofore poorly represented in museum collections. Experience with the living frogs in their natural habitats has been helpful in defining the species and in formulating ideas concerning their […]

A desire to extend the knowledge of, and by so doing to extend the love for, those sunny creatures called Butterflies, has prompted the author to undertake this little work, which, though making no pretence to a technically scientific character, will, it is hoped, be found sufficiently complete and accurate to supply all information needful […]

My duty, in acknowledging the great obligations under which I lie to many naturalists, affords me most sincere pleasure. I had originally intended to have described only a single abnormal Cirripede, from the shores of South America, and was led, for the sake of comparison, to examine the internal parts of as many genera as […]