11 PREFACE. 



To sucli as may be inclined to object to the theoretical views 

 which run through and connect these anatomical details, I would 

 only say, that we shall be quite satisfied, if on finding the latter 

 correct, they will allow us to retain the former for future use : 

 feeling assured, that " there is a certain analogy, constancy, and 

 uniformity in the phenomena or appearances of nature, which 

 are a foundation for general rules" : and that " these are a 

 grammar for the understanding of nature, or that series of effects 

 in the visible world, whereby we are enabled to foresee what will 

 come to pass in the natural course of things." 



JOHN GOODSIR. 



EDINBURGH, 1845. 



