332 Agassiz’s Contributions to the 
wear in the breeding season, etc. All this should be ascertained for each, 
and no species can be considered as well defined and satisfactorily char- 
acterized, the whole history of which is not completed to the extent 
alluded to above.”—pp. 167-169. 
mations, and we shall have to deal with them as well as we can, as ae 
The citations which have been made are unavoidably an my 
veloped 
further explanations. As Prof. Agassiz has stated, the 0 articn 
ness of the system of ideas, and the correctness of any Pa? 
