n DEVELOPMENT 81 



his relations to the under- world of life ; while 

 that which remains a dim suspicion for the 

 unthinking, becomes a vast argument, fraught 

 with the deepest consequences, for all who are 

 acquainted with the recent progress of the ana- 

 tomical and physiological sciences. 



I now propose briefly to unfold that argument, 

 and to set forth, in a form intelligible to those 

 who possess no special acquaintance with ana- 

 tomical science, the chief facts upon which all con- 

 clusions respecting the nature and the extent of 

 the bonds which connect man with the brute 

 world must be based : I shall then indicate the 

 one immediate conclusion which, in my judgment, 

 is justified by those facts, and I shall finally 

 discuss the bearing of that conclusion upon 

 the hypotheses which have been entertained re- 

 specting the Origin of Man. 



The facts^ to which I would first direct the 

 reader's attention, though ignored by many of the 

 professed instructors of the public mind, are easy 

 of demonstration and are universally agreed to by 

 men of science ; while their significance is so 

 great, that whoso has duly pondered over them 

 will, I think, find little to startle him in the 

 other revelations of Biology. I refer to thoso 

 facts which have been made known by the study ^ 

 of Development. 



It is a truth of very wide, if not of universal, 

 170 



