REPORT OF THE SECRETARY. 23 



studying the relations of nearly sixty thousand specimens of the birds 

 of North America. 



The object of the collection we have just described is exclusively the 

 advance of science. The specimens require comparatively but little 

 space for use and preservation. Not being intended for public exhibition 

 they need not be mounted, but may be kept in drawers, or packed away 

 in labeled boxes or casks until wanted for a special investigation. 



Another class of large museums are of a mixed character, combin- 

 ing in their object scientific investigation with special systematic and 

 collegiate instruction. Of this class is the great museum at Cambridge, 

 supported principally by the State of Massachusetts, and under the 

 direction of Professor Agassiz. This museum, which may be consid- 

 ered a model of its class, embraces — first, an immense number of origi- 

 nal specimens, in the study and description of which a number of 

 accomplished naturalists are continuously employed ; second, a series 

 of specimens which have been scientifically described, and so arranged 

 in accordance with their affinities as to enable the student in any 

 branch of natural history to obtain, with the least expenditure of labor, 

 a definite knowledge of what is known of the objects to which he is 

 devoting his attention ; third, a series of specimens of genera so 

 arranged as to serve as illustrations of tbe courses of lectures to 

 the students of tbe university on such general principles of natural 

 history as form an essential part of a liberal education. This museum, 

 therefore, affords ample means for the advancement of science by origi- 

 nal investigation ; for the special training of students who desire to 

 devote themselves to natural history, and for collegiate instruction, 

 while the facilities which it is calculated to afford in these lines are only 

 limited by the funds which it can command. 



Another class of museums supported at the public expense are those 

 intended almost exclusively for popula* instruction and amusement. 

 Museums of this class have been established in several of the principal 

 cities of Great Britain, and I doubt not that the beneficial effects they 

 are producing will induce other cities to follow their example. The 

 most important of these is the one at Liverpool, in which series of 

 generic specimens are admirably mounted and so arranged as to clearly 

 exhibit their relations and affinities. They are, moreover, all distinctly 

 labeled, so that the visitor, almost without an effort, receives definite 

 impressions, valuable in themselves, and which, by association of ideas, 

 become more important as centers around which other ideas, derived 

 from future reading and observation, may be clustered. The impres- 

 sions made through the eye are not only the most definite, but also the 

 most indelible. Museums of this kind ought to be established at the 

 public expense in every city or community which can afford the means 

 for their support. So popular are collections of objects of natural his- 

 tory and ethnology, that large establishments of mere heterogeneous 

 materials are frequently sources of profit to those to whom they belong. 



