566 The American Naturalist. [July, 
some such original tendency or aim, evolution would never have reached 
it present culmination in man.” He quotes Boveri that “ there is too 
much intelligence in nature for any purely mechanical theory to be 
possible.” It is curious that these authors do not perceive that the 
sensation of protoplasm, (consciousness), furnishes the basis for the 
exhibition of the intelligence which they observe, and which has itself 
undergone evolution coincidentally with the organism. Both orthodox 
and heterodox evolutionists (theologically speaking) seem equally slow 
to adopt this view. 
Prof. Tyler’s book is eminently moderate and senscinable, and will 
introduce evolution to a large class of readers in an agreeable form. 
Mg 
3 
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a 
i 
Cope on the Factors of Organic Evolution.’™—This book is : 
divided into three parts: I, The nature of variation; II, The causes of ; 
variation ; III, The inheritance of variation. In the first part it is 
endeavored to show that variation is not promiscuous or multifarious, 
but pursues direct courses towards definite ends. This is done by pre- 
senting the variations of existing species as to color and structure, and 
by an examination of the series presented by the forms of vertebrate 
life in past geologic ages. The latter presentation is a general phy- 
logeny of the vertebrata, with special sections on that of the horse and 
that of man. The second part is divided into chapters which deal 
with the physical energies as causes of variation, and the effects of 
molar motion as seen in variation. These methods of evolution are 
termed respectively physiogenesis and kinetogenesis. Especial atten- 
tion is given to kinetogenesis in connection with the phylogeny of ver- 
tebrates, since it is in these two fields that most of the original work of — 
the author has been done. The author has demonstrated that the 
. primary cause which has moulded the vertebrate skeleton is molar 
motion. In the third part, the inheritance of the characters so ~ 
produced is shown to be the rule, thus demonstrating the inheritance 
of acquired characters. Theories of inheritance are discussed, and that 
one which asserts the transmission of energies to the germ plasma is _ 
defended. These energies are believed to be the results of a composi- 
tion between inherited and acquired energies, the whole of them being 
_ referred to a class distinct from the inorganic energies, which he has — 
named Bathmic. The last chapter in this part is devoted to a considera- 
tion of the relation of consciousness to movements, and hence as a cause 
3 The Primary Factors of Organic Evolution, by E. D. Cope, Professor of Zo- 
ology and Comparative e Anatomy in the eny nem of Pennsylvania. Chicago : 
= Court Pub. Co., is 1896, ppa 
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