150 Book Notices. 
metamorphoses go on in the eggs of all living beings has not yet put us 
on the track of the forces by which the changes they undergo are brought 
about, it is not likely that by mere guesses we shall arrive at any satis-. 
factory explanation of the very origin of these beings themselves. 
atever views are correct concerning the origin of species, one thing 
is certain, that as long as they exist they continue to produce gen- 
eration after generation, individuals which differ from one another only 
in such peculiarities as relate to their individuality. The great defect in 
Darwin’s treatment of the subject of species lies in the total absence of 
an tement respecting the features that constitute individuality. 
Surely, if individuals may vary within the limits assumed by Darwin, he 
was bound first to show that individuality does not consist of a sum of 
investigations have been made. It is known, that every individual egg 
undergoes a series of definite changes before it reaches its mature condi- 
tion; that every germ formed in the egg passes through 
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metamorphoses efure it assumes the structural features of the adult; 
of the species, and therefore as transient as the individuals; while the 
specific characters are forever fixed. i 
the first time made known that species under the name of Turdus 
migratorius, and not one of the specimens observed by Linnzus ag 
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its nest, in its eggs, in its young, as much as in the appearance of the 
ult; not in all the individuals of any particular district, for the ger 
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Ps pe is not individual peculiarity is inicdaatigly and integrally reproduced while 
constitutes individuality, as such, constantly disappears. 
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