Report of TJiird Class, Second Department (Zoology) . 

 By Geo. T. Stevens, M.D. 



[Read before the Institute, March 7, 1871. J 



We find, in summing up the progress of investigations 

 in zoology during the past year, that notwithstanding the 

 really great accumulation of facts that has been made, and 

 the many earnest discussions upon subjects pertaining to 

 this branch of science, there have yet been no startling ad- 

 vances to record either in zoological or biological science, 

 and whatever views we may hold regarding the now much 

 debated question of evolution of living things, it is certain 

 that zoological and biological science have never been ob- 

 jects of special creation, but are the result of long and 

 slow processes of evolution. The science of zoology has 

 passed through certain degrees of progression and of de- 

 velopment which have not in all cases, at first, seemed in 

 the line toward perfection. These apparently retrograde 

 steps are not necessarily what they seem, and may some- 

 times prove essential grades in the true advancement of 

 science. Thus, from the early and crude attempts to 

 arrange and classify animals to the far more complete sys- 

 tem of Linnaeus was indeed a great advance, but when 

 Cuvier gave to the world his new classification based upon 

 internal organization, it seemed to require only the patient 

 labor and the great genius of such thinkers as Agassiz and 

 his co-workers to complete what has so long and so proudly 

 been called the natural system, so as to make it really ex- 

 press the actual relations found in nature. 



Yet notwithstanding the almost universal acceptance of 

 this beautiful system, Lamarc with equal enthusiasm and 



