34 Revieu's — Prof. A. Gandnj — On EL-oIuUon. 



cTionellcB prove that Nature in those ancient days presented certain 

 phases of resemblance with those of to-day. 



The Mollnsca of primai-y periods have also many types which 

 unite them to our day. 



The multitude of variations which M. Barrande has shown in the 

 Cephalopoda, especially in Orthocerns and Cyrtoceras, proves, that 

 the specific form is a somewhat indefinite, transient, and ephemeral 

 character. 



It may seem difficult to conceive how Cephalopods with a calotte 

 (hood), said to be initial, have become Cephalopods with a spherical 

 nucleus, or how they can have passed from one to the other. We 

 must confess, their transition has not yet been observed. But the 

 characters of the siphon, of the septa, and of the curA^ature, and the 

 aperture of their shells have shown transitions. 



" As in the Mollusca, so the Trilobites have given a striking 

 proof of the simplicity of the means by which nature produces the 

 most diverse appearances. The differences arising from individual 

 metamorphosis are actually greater than are their specific differences. 



" However strange and remarkable may be the ancient Merosto- 

 mata, the genera Bellinurus and PrestwicMa have connected them 

 with the ZiimuU of the present day. 



" The Ostracoda and the Insecta of ancient days were, we may 

 conclude, like those of the present epoch. 



" Many fishes have afforded us characters which induce us to con- 

 sider these fossil forms as the younger state of the class Pisces. 



"Some of the ancient Eeptiles, Avhich had incompletely-ossified 

 vertebrae and cartilaginous extremities to their limb-bones, are 

 equally difficult to understand, except as representing the young 

 state of the reptilian class. 



" Thus the patient study of facts reveals connexions between the 

 beings of past ages." 



" I have difficulty in believing," wrote D'Omalius de'Halloy, at 

 the end of his life, " that the Almighty Being, whom I consider the 

 Author of Nature, should have at different epochs destroyed all 

 living beings in order to enjoy the pleasure of re-creating new ones, 

 which, on the same general plans, presented successive differences 

 tending to culminate in the present living forms." " This language 

 seems to me to be that of common sense." 



" The examination of the primary fossils leads us to accept the 

 conclusion that there exists a passage from species to species and 

 from genus to genus, and from family to family "■ (and one might 

 add, in all probability, from Class to Class ! — Edit.). 



" But to keep within the exact truth, we must add that the present 

 state of science scarcely allows us to go beyond this. It does not 

 allow us to pierce the mystery of the primitive development of the 

 great classes of the animal kingdom." 



"No man knows how the first individuals of the Foraminifera, of 

 the Coelenterata, the Starfish, the Crinoids, the Echini, and the 

 various other classes were formed which appear in the Primary 

 rocks. In the Lower Cambrian of St. Davids we already see 



