592 A Century's Progress in American Zodlogy. (October, 
Barton, and Harlan were born in Philadelphia and taught anatomy 
there. Godman was born in Annapolis, and lectured on anatomy 
in three medical colleges, but not in Philadelphia. On the whole, 
American zodlogy took its rise and was fostered chiefly in Phil- 
adelphia by the professors in the medical schools ; and zodlogy 
the world over may be said to have sprung from the study of 
human anatomy, as taught at the anatomical centres of Italy, 
France, England, and Germany. 
The last half-century of progress in zodlogy in America may 
be divided into three epochs : — 
(1.) The epoch of Systematic Zodlogy, during which a few 
physiological essays appeared. To this department of zodlogy a 
most decided impulse was given by the Smithsonian Institution, 
which went into active operation in 1847, while the study of the 
fossil forms (paleontology) was greatly accelerated by the influ- 
ence of national and especially state surveys. 
(2.) The epoch of Morphological and Embryological Zoölogy. 
This period is due to the arrival of Louis Agassiz in this country, 
in 1846, resulting in his lectures on comparative embryology 
and the foundation of the Museum of Comparative Zoology, 
where American students, who were attracted by the fame of 
Agassiz, were instructed in the methods of Cuvier, Von Baer, 
Déllinger, and Agassiz himself, and zodlogy was studied from 
the side of histology and embryology, while paleontology was 
wedded to the study of living animals. i 
(8.) The epoch of Evolution, or the study of the genetic re- 
lationship of animals, based on their mutual relations and their 
physical environment. This period dates from the publication of 
Darwin’s Origin of Species, in 1859. ; 
Turning, now, to the first epoch, — that in which American 
systematic zoölogy took its rise, — we find that work was done 
which must necessarily precede more important studies on the 
embryology, geographical distribution, mutual relations, and psy- 
chology of animals, and which exerts a marked influence On the 
classification of animals, which nowadays is equivalent to pi 
their genetic relationships; for the time is past when the ani 
world should be regarded as comprised within separate sub-king- 
doms, between which there is no morphological or genetic s 
nection. 
The systematic works are so well known and our space a 
limited that we shall merely enumerate the names of our pe 
zoological authors. In the study of mammals the works of pes 
dubon and his predecessors, already named, and of Thomas 
