CLASSIFICATION. 417 



With the progress of botany intermediate and ad- 

 ditional divisions have gradually been introduced. Ac- 

 cording to the Laws of Botanical Nomenclature adopted 

 by the International Botanical Congress, held at Paris u 

 in August, 1867, n I GSS than twenty-one names of classes 

 are recognised namely, Kingdom, Division, Sub-division, 

 Class, Sub-class, Cohort, Sub-cohort, Order, Sub-order, 

 Tribe, Sub-tribe, Genus, Sub-genus, Section, Sub-section, 

 Species, Sub-species, Variety, Sub- variety, Variation, 

 Sub-variation. It is allowed by the authors of this 

 scheme, that the definition or degree of importance to be 

 attributed to any of these terms may vary in a certain 

 degree according to individual opinion. The only point 

 on which botanists are not allowed discretion is as to 

 the order of the successive sub-divisions ; the division of 

 genera into tribes, or of tribes into orders ; any inversion, 

 in short, of the arrangement being inadmissible. There is 

 no reason to suppose that even the above list is complete 

 and inextensible. The Botanical Congress itself recognised 

 the distinction between variations according as they are 

 Seedlings, Half-breeds, or Lusus Natures. The compli- 

 cation of the inferior classes is increased again by the 

 existence of hybrids, arising from the fertilization of one 

 species by another deemed a distinct species, nor can we 

 place any limit to the minuteness of discrimination of 

 degrees of breeding short of an actual pedigree of descent. 



It will be evident to the reader that in the remarks 

 upon classification as applied to the Natural Sciences, 

 given in this and the preceding sections, I have not in the 

 least attempted to treat the subject in a manner adequate 

 to its extent and importance. A volume would be insuf- 

 ficient for tracing out the principles of scientific method 



u ' Laws of Botanical Nomenclature,' by Alphonse Decandolle, trans- 

 lated from the French, 1868, p. 19. 

 VOL. II. E e 



