1849-52-] PRIXUJ'LES OF ZOOLOGY. 31 



a monograph in two parts, in the " Memoirs of the 

 American Academy of Sciences," of which the sixteen 

 quarto plates, drawn on stone from nature by Sonrel, 

 are simply superb. This first contribution of Agassiz 

 to the natural history of the United States marks a new 

 departure in America, in that it shows the structure, 

 the generic peculiarities, and all the characters of the 

 muscular system in very low animals. 



Agassiz gave a great part of his time also to directing 

 the publication of his volume on Lake Superior. Curi- 

 ously enough, he wholly abandoned his " Principles of 

 Zoology." His collaborator, Dr. A. A. Gould, wrote, 

 during 1849 and 1850, the second part, as he had already 

 written with success the first part; but from year to year 

 Agassiz delayed reading and correcting the manuscript, 

 until it was too late to publish it. It was one of the 

 foibles of the great naturalist not to finish promptly the 

 work already begun, but to let it drop in order to under- 

 take other work. However, the success of the first part 

 on " Comparative Physiology," which was issued in 1848, 

 was great, and several editions were printed. The work 

 was quickly pirated in England by unscrupulous edi- 

 tors. A German translation by Professor Bronn, the 

 celebrated palaeontologist of the University of Heidel- 

 berg, was published at Stuttgart in 1851; and a 



r 



French translation, by the great geographer Elisee 



/ 



Reclus, was printed in Paris, in the " Magasin d' Edu- 

 cation et de Recreation," as late as 1891, under the 

 title " Principes de Zoologie." The work had great 

 influence in America, the three editions of 1848, 1851, 

 and 1 86 1 being extensively used by professors and 



