242 On Lamprey Eels — {Petromyzontidce) 



cannot but discern a special adaptation in the structure of Serpents 

 to their commonly prone positon, and a prevision of the dangers to 

 which they were subject from falling bodies, and the tread of heavy 

 beasts. I might enumerate many other equally beautiful instances 

 of design and foresight, — the whole organization of the Serpent is 

 replete with such — in relation to the necessities of their apodal 

 vermiform character ; just as the snake-like eel is compensated by 

 analogous modifications amongst fishes, and the snake-like centipede 



amonorst insects. 



But what more particularly concerns us in the relation of the ser- 

 pent to our own history, is the great and significant fact revealed by 

 palaeontology, viz., that all these ophidian peculiarities and com- 

 plexities of cranial and vertebral organization, in designed subser- 

 viency to a prone posture, and a gh^ling progress on the belly, were 

 given by a beneficent Creator to the serpents of that early tertiary 

 period of our planet's history ; when, in the slow and progressive 

 preparation of the earth, the species which are now our contem- 

 poraries were but just beginning to dawn ; these, moreover, being 

 species of the lowest classes of animals, called into existence long be- 

 fore any of the actual kinds of mammalia trod the earth, and long 

 ages before the creation of man. — A History of British Reptiles, by 

 Professor Richard Owen. Part III., p. 151. 



On Lamprey Eels — {Petromyzontidce) — and their Embryonic 

 Development and Place in the Natural History System. 



There are families in all departments of nature, whose 

 peculiarities call for an investigation of their more general 

 relations rather than of their structural details. The Petro- 

 myzons are in this case. Closely allied together and circum- 

 scribed in a most natural family, it is a question whether 

 they should be entirely separated from all other fishes to 

 form a great group by themselves, or whether they belong to 

 one of those great divisions in which the individual members 

 differ widely from each other. In other words, should the 

 Petromyzons stand by themselves in a natural classification 

 of fishes, as Prince Canino and Joh. Miiller have placed them, 

 or shall we combine them with skates and sharks, as Cuvier 

 has done ? To answer such a question, it is necessary to 

 discuss beforehand principles of the utmost importance in the 

 study of natural history, and above all to settle the following 

 difficulty : — Is the study of anatomical structure an abso- 



