PREFATORY NOTE. 



IN the spring of 1866, a desire was expressed by the Class to 

 have the author's Lectures on Comparative Anatomy and Zoology 

 published for distribution. Nothing definite, however, was determ- 

 ined upo.1 until the following spring, when arrangements were en- 

 tered into which have resulted in the appearance of this little 

 volume. It is in many respects somewhat fuller than a synopsis, 

 which, however, in general features, it resembles. Although pre- 

 pared in answer to the expressed needs of a class composed chiefly 

 of Medical Students, it is hoped that it may not be without value to 

 the cultivators of rational anatomy elsewhere. 



In the attempt, apparent in different portions of the book, to frame 

 general definitions and give brief classifications of anatomical sys- 

 tems, the author is fully aware of the liability to error thus incurred. 

 Any conclusions based upon the present state of a science so ac- 

 tively cultivated as Comparative Anatomy may eventually prove 

 of but doubtful utility. It is easy to group about assumed stand- 

 points the observations of others, but more difficult to preserve in 

 such arrangements harmony between the old and new facts. In 



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