XXIV HISTOllICAL PBEFACE. 



Lawrence were continuing their studies and writings, and many other names of lesser 

 note were contributing their several shares to the whole result : the figure of John Cassin 

 stands prominent. Cassin was born September 6, 1813, and passed from view in the 

 Quaker Cit)', January 10, 1869. Numerous valuable papers and several important works 

 attest the assiduity and success with which he cultivated his favorite science to the end 

 of his days. I think that his first paper was tlie description of a new hawk, Cymindis 

 wilsoni, in 1847. Among liis most important works are the Ornithology of the Wilkes 

 Exploring Expedition ; of the Perry Japan Expedition ; and of the Gilliss Expedition to 

 Chili. Aside from his strong cooperation with Baird in the great work to be presently 

 noticed, Cassin's seal is set upon North American ornithology in the beautiful book 

 begun in 1853 and finished in 1856, entitled "Illustrations of the Birds of California," 

 etc., forming a large octavo volume, illustrated with fifty colored plates. His distinc- 

 tive place in ornithology is this : he was the only ornithologist this country has ever 

 produced who was as familiar with the birds of the Old World as with those of America. 

 Enjoying the facilities of the then unrivalled collection of the Philadelphia Academy, his 

 monographic studies were pushed into almost every group of birds of the world at 

 large. He was patient and laborious in the technic of his art, and full of book-learning 

 in the history of his subject ; with the result, that the Cassinian period, largely by the 

 work of Cassin himself, is marked by its " bookishness," by its breadth and scope in 

 ornithology at large, and by the first decided change since Audubon in the aspect of the 

 classification and nomenclature of the birds of our country. The Cassinian period marks 

 the culmination of the changes that wrought the fall of the Audubonian sceptre in all 

 that relates to the technicalities of the science, and consequently represents the beginning 

 of a new epoch. 



The peers of this period are only three, — Lawrence, Brewer, and Baird. The for- 

 mer of these, already an eminent ornithologist, continued his rapidly succeeding papers 

 and was preparing his share of Baird's great work of 1858 ; though later his attention be- 

 came so closely fixed upon the birds of Central and South America, that a '* Lawrencian 

 period " is to be found in the history of the ornithology of those countries rather than 

 of our own. Dr. Brewer's various articles appeared, and in 1857 this author, so well 

 known since Audubonian times, became the recognized leading oologist of North America, 

 through the publication of the first part of his " North American Oology " — a work unfor- 

 tunately suspended at this point. Though thus fragmentary, this quarto volume stands 

 as the first systematic treatise published in this country exclusively devoted to oology, and 

 giving a considerable series of colored illustrations of eggs. But a larger measure of the 

 world's regard became his much later, when, in 1874, appeared the great " History of North 

 American Birds," in three quarto volumes, all the biographical matter of which was by 

 him ; and, even as I write, two more volumes are about to appear, in which he has like 

 large share. Thus closely is the name of Brewer identified with the progress of the 

 science for nearly half a century, — from 1837 at least, to 1884, some four years after his 

 death, which occurred January 23, 1880. He was born in Boston, November 21, 1814. 



Baird published little during the Cassinian period, being then intent upon the great 

 work about to appear ; but the number of workers in special fields attests the activity 

 of the times. S. W. Woodliouse published his completed observations upon the birds 

 of the Southwest in an illustrated octavo volume. Zadock Thompson's " Natural History 



