For example , certain names assigned by William Bartram in his catalog of 1791 were now deemed unusable .
As scientific knowledge expanded quickly in the second half of the nineteenth century , the need for reorganizing the system of names used to describe North American birds grew commensurately .
Certain names assigned by William Bartram in his catalog of 1791 were now deemed unusable .
As scientific knowledge expanded quickly in the second half of the nineteenth century , the need for reorganizing the system of names used to describe North American birds grew commensurately .