W. B. DWIGHT. 5 5 



First, those pertaining to the general philosophy of 

 animal life, such as anatomy, or the study of animal 

 structure ; comparative anatomy, treating of the rela- 

 tions of structure in different types of animals ; phy- 

 siology, treating of the active functions of animals ; his- 

 tology, the minute study of tissues ; osteology, the study 

 of bones ; psychology, the study of faculties of mind and 

 instinct ; embryology the study of mode of development 

 from the embryo to maturity ; zoo-geography, the dis- 

 tribution of animals ; microscopic zoology, the adapta- 

 tion of the microscope to the study of animal life. 



Second, those growing out of the classification of the 

 immense number of groups of animals, such as entomol- 

 ogy, or study of insects ; herpetology, the study of 

 snakes ; ornithology, the study of birds ; malacology 

 or conchology, the study of mollusks, and the separate 

 studies of fishes, corals, spiders, etc. 



Everyone of the these subdivisions, and many others, 

 constitutes an important field which may well engross 

 the life-work of any scientist of the amplest powers. 



Other fields of scientific labor would show a similar 

 tendency towards specialization. 



Another good method of realizing the intense special- 

 ization of to-day, as compared with the past, is to com- 

 jjare the text-books of to-day with those of former days. 

 Let me call your attention to two representative books 

 of scientific instruction in the sixteenth and seventeenth 

 centuries. Specimens of the volumes themselves — the 

 rarest of books in this country, at least — have been 

 kindly loaned to me for this occasion by their distin- 

 guished owner, Hon. Henry Barnard, of Hartford, Conn. 

 One is the Orbis Sensualium Pictus, (i. e. , The Illus- 

 trated World of Material Objects,) by Comenius, pub- 

 lished at Nuremberg, in 1658. The other is the Philo- 

 sopMca Margarita, or, Scientific Pearls, by Reish, pub- 

 lished in 1518. Of these two small books, the first was 



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