HUGH MILLER. XXXVIL 



get logical £,cience, however, does not permit us to remove, for 

 the present, the veil which hangs over this mysterious chrono- 

 logy ; but our author is of opinion that in about a quarter 

 of a century, in a favoured locality like the British islands, 

 geological history " will assume a very extraordinary form." 



It is a singular fact, which will yet lead to singular re- 

 sultj, that Cuvier's arrangement of the four classes of verte- 

 brate animals should exhibit the same order as that in which 

 they are found in the strata of the earth. In the^sA, the 

 average proportion of the brain to the spinal cord is only as 

 2 to 1. In the reptile^ the ratio is as 2^ to 1. In the hird^ 

 it is as 3 to 1. In the mammalia, it is as 4 to 1 ; and in 

 man, it is as 23 to 1. No less remarkable is the foetal pro- 

 gress of the human brain. It first becomes a brain resem- 

 bling that of a fish ; then it grows into the form of that of 

 a reptile ; then into that of a bird ; then into that of a mam- 

 miferous quadruped; and finally it assumes the form of a 

 human brain; "thus comprising in its festal progress an 

 epitome of geological history, as if man were in himself a 

 compendium of all animated nature, and of kin to every crea- 

 ture that lives." 



With these considerations, Mr Miller has brought his 

 subject to the point at which science, in its onward progress, 

 now stands. It is to embryology we are in future to look 

 for further information upon the most intimate relations 

 which exist between all organized beings. We may fairly 

 entertain the hope that the time is not far when we shall not 

 only fully understand the plan of creation, but even lift some 

 corner of the veil which has hitherto prevented us from form- 

 ing adequate ideas of the first introduction of animal and ve- 

 getable life upon earth, and of the changes which both king- 

 doms have undergone in the succession of geological ages. 



L. AGASSIZ. 

 Cambridge, ScDtember 1850. 



