Revieivs — Dr. Chapman^ s Evolution of Life. 279 



different forms of life thronglioiit time. So hard is it to realize the 

 truth of the old adage that " Fact is often stranger than Fiction." 



This may appear rather a long prelude to our notice of Dr. Chap- 

 man's book, but, perhaps, it may not be altogether useless, as the 

 work before us is not a record of new facts, but a condensed view, in- 

 tended for popular reading, of the most important generalizations in 

 reference to the structure of plants and animals, their petrified remains, 

 and mode of development, and showing how the doctrine of the 

 Evolution of Life is borne out by the facts of Botany, Zoology, Geo- 

 logy, and Embryology. It would be out of place here to discuss the 

 questions raised in all these departments of natural science : we must . 

 confine ourselves to the geological section, and, indeed, the results of 

 palgeontological investigation have, perhaps, the most important 

 bearing on all questions of Evolution. 



This bearing is discussed by Dr. Chapman in his section Geology. 

 He gives a brief sketch of geological reasoning, and points out the 

 liability of error into which many observers fall, from applying 

 generalizations drawn from limited data to the whole world. This 

 is particularly the case in determining the relative ages of rocks in 

 widely distant areas. This, however, does not affect Palaeontology 

 when looked upon in a purely zoological light, or when brought to 

 bear upon the subject of Evolution. Drawing attention first to the 

 life of the Silurian period. Dr. Chapman points out that the forms of 

 life are the most simply organized of the respective divisions of the 

 animal or vegetable kingdom to which they belong. Thus the 

 Crinoids and Starfish were the oldest of the Echinodermata, the 

 Brachiopoda of Mollusca, the Entomostraca of Crustacea, the Worms 

 preceded the Insects, and the Fucoidse were the earliest t3qDes of 

 vegetable life. In the Old Eed Sandstone period we find remains of 

 Fish, a few Ferns, Lycopods and Conifers ; the Fishes are of the 

 Shark tribe and Ganoids, not so highly organized as the Teliosts of 

 the present day ; and the Ganoids he considers to be the common 

 stock from which the Teliosts and Batrachia diverged. In the 

 Carboniferous period we find Ferns in great variety and Lycopod-like 

 plants of luxuriant growth ; the Batrachia first appear, together with 

 the Centipedes, the May-fly, Locust and Beetle orders among Insects. 

 In the Permian rocks remains of the simplest reptile, the Protero- 

 saurus, occur; while in the Triassic period we have not only Batrachia 

 and Eeptiles, but Birds and Mammalia (Marsupials). Among the 

 Birds the Brontozoon of the Connecticut valley must have been four 

 times as large as the Ostrich. Dr. Chapman observes that the 

 existence of such large birds at this period is in harmony with 

 the view of the Reptiles being the progenitors through the Ostrich 

 family of the Birds; while the fact of both Birds and Mammals 

 appearing about the same time confirms the theory that they are the 

 diverging stem of a common stock, the Reptilia. In the Jurassic 

 period we find a great variety of Reptiles : the Ichthyosaurus and 

 Flesiosaurus are considered to unite in tbeir organization reptilian 

 with batrachian and piscine characters. The Campsognathus, a bird- 

 like reptile, and the ArchcBopttryx, a reptile-like bird, tend to bridge 



