xxi.] CLASSIFICATION. 727 



With the progress of botany intermediate and additional 

 groups have gradually been introduced. According to the 

 Laws of Botanical Nomenclature adopted by the Inter- 

 national Botanical Congress, held at Paris 1 in August 

 1867, no less than twenty-one names of classes are re- 

 cognised 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 rank or 

 degree of importance to be attributed to any of these divi- 

 sions 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 ; 

 any inversion of the arrangement, such as division of a 

 genus into tribes, or of a tribe into orders, is quite inad- 

 missible. 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 

 Naturae. The complication of the inferior classes is in- 

 creased again by the existence of hybrids, arising from the 

 fertilisation 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 individuals. 



It will be evident to the reader that in the remarks 

 upon classification as applied to the Natural Sciences, 



E'ven in this and the preceding sections, I have not in the 

 ast 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 

 specially applicable to these branches of science. What 

 more I may be able to say upon the subject will be better 

 said, if ever, when I am able to take up the closely- 

 connected subjects of Scientific Nomenclature, Terminology, 

 and Descriptive Representation. In the meantime, I have 

 wished to show, in a negative point of view, that natural 

 classification in the animal and vegetable kingdoms is 

 a special problem, and that the particular methods and 

 1 Laws of Botanical Nomenclature, byAlphonse Decandoile, trans- 

 ited from the French, 1868, p. 19. 



