of the Mineral and Mosaical Geologies. 321 



creation are to be interpreted as six natural days, and not as so 

 many periods of indefinite length. 



The last passage we have quoted from our author, will serve to 

 shew the gentlemanly tone he has assumed, and the respectful 

 terms in which he speaks of Professor Buckland, whenever he has 

 occasion to mention him personally — a respect most eminently his 

 due, and in which with all our heart, we sincerely concur. A 

 similar tone prevails throughout the whole work, and though the 

 arguments with which Mr. Penn supports his own views, are 

 strong and powerful, they are urged with mildness and urbanity. 

 If they do not convince, they cannot offend. 



But we must not in justice, either to our author, or ourselves, 

 take leave of him with mere negative commendation. We think 

 he has fully made out his case, and if any thing was wanting to 

 satisfy us of the stability of the reasonings contained in the Com- 

 parative Estimate, and the accuracy of the conclusions deduced 

 from them, they are in our opinion, amply supplied in the Supple- 

 ment to this admirable work. 



III. Lectures on Comparative Anatomy, in which are explained 

 the Preparations in the Hunterian Collection, illustrated by 

 Engravings; to which is subjoined " Synopsis Systematis lie gni 

 Animalis nunc primum ex Ovi Modificationibus propositum," 

 by Sir Everard Home, Bart., V.P.R.S., F.S.A., F.L.S., &c. 



In resuming an account of this splendid work, we must, as in the 

 former article (p. 134), limit ourselves to its principal features only, 

 selecting especially for our readers' notice the new facts which it 

 embraces, and the new views which it discloses and illustrates. 



In the first place, we cannot omit recording in our pages the 

 extraordinary fact, first published by the author, of an animal, (the 

 Dugong, in the Eastern Seas, and the Manatee in the great rivers 

 of the Western Continent,) in which the heart is divided into two 

 distinct portions of similar structure and equal force, the blood in 

 its passage through the lungs requiring the same impetus as in 

 passing through the different parts of the body. There is also a 

 curious account of a nearly complete fossil skeleton, illustrated by 

 engravings, which forms in itself, an important and distinct class 

 of the antediluvian animals no longer met with on our globe. 

 He gives it the name Protcosaurus, as the class to which it belongs 

 is intermediate between the lizard and Proteus. 



On the subject of generation, the author has taken particular- 

 pains, and has certainly been fortunate in his researches. The 

 discovery of the human ovum appears to please him more than any 



Vol. XVI. Y 



