262 LAKE SUPERIOR. 



ment of individual animals ; and, indeed, I can now show, through all 

 classes of the animal kingdom, that the oldest representatives of any 

 family agree closely with the embryonic stages of the higher types of 

 tlie living representatives of the same families ; or, in other words, 

 that the order of succession of animals, through all classes and 

 families, agrees, in a most astonishing measure, with the degrees of 

 development of young animals of the present age. 



This being the case, it is obvious that a minute investigation of the 

 embryology of Lepidosteus would throw a vast amount of light upon 

 the history of the succession of fishes, of all geological periods ; and 

 also would probably give the first indication of the manner in which 

 the separation of true ichthyological characters from reptilian char- 

 acters, was gradually introduced ; as it is more than probable, from 

 all we know otherwise of the embryology of animals, that the young 

 gar-pike, in its earliest condition, will have characters truly ichthy- 

 ological, and only assume, gradually, the peculiar reptilian charac- 

 ters which distinguish it. But notwithstanding all my efforts to 

 secure the Lepidosteus in the breeding season, I have failed up to 

 tliis day to gain the desired information. It only remains for me, 

 therefore, to urge naturalists living near the waters inhabited by 

 Lepidosteus to take up the subject as early as an opportunity is 

 afforded them. 



Although Lepidosteus does not occur in Lake Superior, I have 

 deemed it sufficiently important to introduce these remarks here, as 

 this fish occurs in all the northern lakes except Lake Superior, as 

 far north even as Mud Lake, below Sault St. Marie. Its presence 

 in these waters is another of the striking differences which exist 

 between the ichthyological fauna of Lake Superior, and that of the 

 other lakes ; and shows once more, within what narrow limits animals 

 may be circumscribed, even when endowed with the most powerful 

 means of locomotion, and left untrammeled by natural barriers. 



This Lepidosteus is one of the swiftest fishes I know. He darts like 

 an arrow through the waters, and the facihty with which he overcomes 

 rapids, even the rapids of the Niagara, shows that the falls of St. 

 Mary would be no natural barrier to him, if there were no nat- 

 ural causes to keep him within the limits in which he is found, 

 and which extend from Lake Michigan, Lake St. Clair, and Mud 



