46 Mr. Colebrooke on Arrangements in Natural History. 



circumscribing the solar system. In like manner, the middle points of 

 exterior groups encompassing one interior one, and equidistant from its 

 centre and from each other, should be twelve in number : and this, there- 

 fore, is in fact the proper number of a strictly natural arrangement of 

 objects with relation to one common object of comparison : the normal 

 group is one ; the aberrant twelve, classed for more ready apprehension in 

 form of subordinate clusters. The interior group is single ; the exterior 

 assemblage twelve-fold. This then appears to be the natural arrange- 

 ment: and the subdivision of the inner cluster, and grouping of outer 

 ones, whence quinary arrangements result in both instances, are properly 

 artificial. 



The tendency to the number of five in the classing of natural objects hag 

 been shewn by Mr. W. S. MacLeay in his Horse Entomologicse ; and the 

 subject has been pursued by himself and Mr. Vigors, in essays inserted in 

 the Linnean Transactions. Their attention has been' chiefly, but not 

 exclusively, directed to Zoology. The same principles are applicable to 

 Botany. But, in the present state of the science, no more could be 

 attempted than an approach towards a general distribution of natural 

 orders. The further researches of Botanists will cancel some of the 

 associations now received for natural orders, and establish others; and 

 all which could at present be looked for, would be such an approxima- 

 tion as might make it probable, that, in a more advanced state of the 

 science, the indications would be confirmed. I shall not attempt that 

 distribution; the first steps of which are easy and obvious, but the 

 fiirther gradations unprepared and as yet impracticable. 



