File:Outlines of comparative physiology touching the structure and development of the races of animals, living and extinct - for the use of schools and colleges (1870) (14779710391).jpg

Identifier: outlinesofcompar00agas (find matches)
Title: Outlines of comparative physiology touching the structure and development of the races of animals, living and extinct : for the use of schools and colleges
Year: 1870 (1870s)
Authors: Agassiz, Louis, 1807-1873 Gould, Augustus A. (Augustus Addison), 1805-1866 Wright, Thomas, 1809-1884
Subjects: Physiology, Comparative Zoology
Publisher: London : Bell & Daldy
Contributing Library: MBLWHOI Library
Digitizing Sponsor: MBLWHOI Library

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
erewas, during the palaeozoicage, less variety amongthe animals of the differ-ent regions of the globe ;and this may be readilyexplained by the peculiarconfiguration of the earthat that epoch. Greatmountains did not thenexist; there were neitherlofty elevations nor deepdepressions. The sea co-vered the greater part, ifnot the whole, of the sur-face of the globe; and theanimals which then exist-ed, and whose remainshave been preserved, wereall, with the exception orthe reptiles which haveleft their foot-marks onthe Potsdam sandstone,aquatic animals, breathingby gills. This wide dis-tribution of the waters im-pressed a very uniformcharacter upon the wholeanimal kingdom. Betweendifferent zones and conti-nents, no such strange TC „ , , * ,, -..ff ° rig.JSO.— Coccosteus cuspidatuscontrasts of the different types existed as at the present epoch. The same gen eft;, andoften the same species, were found in the seas of America,Europe, Asia, Africa, and New Holland ; from which we must D D
Text Appearing After Image:
.—.-. /-asa. 402 GEOLOGICAL SUCCESSION OF ANIMALS. conclude that the climate was much more uniform than atthe present day. Among the aquatic population, no soundwas heard. All creation was then silent. § 670. THE SECONDARY AGE. Reign of Reptiles.—TheSecondary age displays a greater variety of animals as well asplants. The fantastic forms of the palaeozoic age disappear,and in their place we see a greater symmetry of shape. Theadvance is particularly marked in the series of vertebrata.Fishes and a few reptiles are no longer the sole representativesof that department. Reptiles, birds, and mammals succes-sively make their appearance, but reptiles preponderate, par-ticularly in the Oolitic formation ; on which account we havecalled this age the Reign of Reptiles. § 671. The Carboniferous formation is the most ancient ofthe Secondary age. Its fauna bears, in various respects, aclose analogy to that of the palaeozoic epoch, especially inits Trilobites and mollusca.* Besides these, we

Note About Images