206 Transactions of the 



forms here come to play an important part. These, when feasible, 

 should be set under the organ and order they belong to. In the 

 case, for instance, of stems, whether of recent or fossil woods, when 

 the genus of the plant is unknown, a geographical division or fit- 

 ness for manufacturing purposes may judiciously guide the arrange- 

 ment. Fossil specimens may even be separated into a subsection 

 where doubt exists as to their exact afiinities. A series illustrating 

 pecuharities in development, to wit, abnormalities in growth, should 

 succeed the physiological. Vegetable fabrics, adulterations, &c,, 

 ought to terminate the vegetable kingdom. 



The ]3rinciples guiding the division of the animal kingdom are 

 in many respects identical with those regulating vegetables. The 

 ascending series is the most rational. From simplicity to com- 

 plexity and the differentiation of organs, thus most naturally and 

 justifiably are followed. 



In the lower animal forms, as in the vegetable world, a slide may 

 contain the entire organism. Here, therefore, a zoological arrange- 

 ment into orders, genera, and species is sufiicient. In higher forms 

 the systems of organs, physiologically or anatomically considered, 

 take the precedence of orders, families, genera, and S2:)ecies. Acces- 

 sory organs connected with or subsidiary to a function follow the 

 organ itself. 



With the great bulk of Microscopic objects, generally speaking, 

 it is not difficult to decide where each ought to be placed in a 

 series arranged in the manner herein proposed. Nevertheless, nu- 

 merous instances may occur in which it is not so easy at once to 

 assign their position. By due consideration, however, of what special 

 topic the slide is meant to illustrate, one may arrive at a conclusion 

 where its nearest allies are to be found in the cabinet ; and by 

 balancing its minor relations we ultimately find a suitable situation 

 for it. 



At first sight a matter such as this may seem of trivial im- 

 portance. But as the whole aim of classifying specimens is, that 

 each should fall into its proper section, where they can be consulted 

 almost without a moment's reflection or loss of time, it behoves that 

 once for all a definite place should be assigned each object, where it 

 may afterwards be readily found when wanted. 



The question has been asked me under what heading ought this, 

 that, and the other thing to be put. 



Now, as I cannot predicate all the possible contingencies which 

 are likely to arise, I must confine myself to a few examples ; leaving 

 specialities to be dealt with in a similar manner according as they 

 may arise. For instance, where is the most fitting situation for 

 such objects as egg-shell, coprohtes, calcuh, pearls, insects in amber, 

 works of art, micrometers, and test-objects ? 



