PROOFS, ILLUSTRATIONS, AUTHORITIES, ETC. ix 



White-fish and the Sturgeon are therefore much more alike. But 

 this similarity is only transient; as the white-fish grows, its verte- 

 brae become ossified, and its resemblance to the Sturgeon is com- 

 paratively slight. As the Sturgeon has no such transformation of 

 the vertebrae, and is in some sense arrested in its development, while 

 the White-fish undergoes subsequent transformation, we conclude 

 that, compared with the White-fish, it is really inferior in rank." 



" [The fishes of the early period] all exhibit certain characteristic 

 features which are very interesting in a physiological point of view. 

 They all have a broad head, and a tail terminating in two equal 

 lobes. What is still more curious, the best preserved specimens 

 show no indications of the bodies of vertebrae, but merely the spinous 

 processes; from which it must be inferred that the body of the 



vertebra was cartilaginous, as it is in our Sturgeons We 



thence conclude that these ancient fishes were not so fully developed 

 as most of our fishes; being, like the Sturgeon, arrested, as it were, 

 in their development; since we have shown that the Sturgeon, in 

 its organization, agrees, in many respects, with the Cod or Salmon 

 in their early age." Agassiz : Principles of Zoology. 



Agassiz says " Life, in animals, is manifested by two sorts of 

 functions : viz., First, the peculiar functions of animal life, or those 

 of relation, which include the functions of sensation and voluntary 

 motion ; those which enable us to approach and perceive our fellow 

 beings and the objects about us, and to bring us into relation to 

 them : second, the functions of vegetative life, which are nutrition 

 and reproduction ; those, indeed, which are essential to the main- 

 tenance and perpetuation of life." 



He says elsewhere " As a general result of the observations which 

 have been made up to this time, on the embryology of the various 

 classes of the Animal Kingdom, especially of the Vertebrates, it may 

 be said that the organs of the body are successively formed in the 

 order of their organic importance, the most essential being always 

 the earliest to appear. In consequence of this law, the organs of 

 vegetative life, the intestines and their appurtenances, make their 

 appearance subsequently to those of animal life, such as the nervous 

 system, the skeleton, etc." 



He makes the same announcement in other terms "in most 

 animals the organs of animal life are precisely those which are 

 earliest formed in the embryo ; whereas those of vegetative life, such 

 as the heart, the respiratory organs, and the jaws, are not distinctly 

 formed till afterwards." See Prin. Zoology, 59, 318, 322. 



Agassiz has laid it down as a principle, that the characters in 

 embryology, the organic gradation of animals, and the appearance 

 of the animals in the succession of ages as displayed by geology, are 

 all in conformity. 



Assuming this to be true, and keeping in view that the nervous 

 system appears in the embryo before the circulatory, respiratory, 

 and other organs of vegetative life, which of the class of fishes should 

 we expect first to be presented on the scene? Undoubtedly, those 



