15 



But in respect to any more general collection, including foreign 

 as well as native species, the principle upon which we ought to 

 act, with a view to educational purposes, is to select from the 

 immense field which nature opens to us, those specimens only 

 which are severally characteristic or typical of the higher groups, 

 — classes, orders, families,— taking in one or more of these groups 

 thus rejiresented according as our space allows, — but excluding all 

 groups of lower value. Or, having formed a British collection, we 

 may intercalate in the arrangement of it type-forms of those 

 larger groups which contain no British representatives. Any 

 considerable number of closely-allied exotic species would be here 

 out of place. They only take up room which might be turned to 

 a more useful account. It is very important that a commencing 

 student of Natural History should have a general knowledge of 

 the whole subject before entering upon any particular branch of it, 

 but that is all he wants. And nothing could be more instructive 

 than a Museum containing a well-arranged series of specimens, by 

 Avhich he might trace the various relationships existing between 

 the larger and well marked groups of animals, — relationships of 

 time as well as of affinity, — not only indicating, as we pass from 

 one to another, the chief modifications of structure upon which are 

 based our principles of classification, but exhibiting likewise, 

 associated with living forms, those lost forms which preceded them 

 in the earlier days of this earth. Or, if we wished to give a 

 general idea of the geographical distribution of animals at the 

 present dny, Ave might select a single species of each class, 

 order or familj^, in a given country, and then show their several 

 representatiA-es in other countries, thus affording a glance of the 

 productions of the whole earth. 



Dr. AYheAvoll has remarked that it is classification, conducted 

 on scientific principles, by which Ave " obtain fixed characters of 

 the kind of things," that " renders exact knowledge and general 

 propositions possible."* Bare " facts are" but " the materials of 



* See " History of the Inductive Sciences," vol. iii., pp. 188 and 227. 



