DE CANDOLLE'S PHYTOGRAPHY. 289 



As De CandoUe points out, there is much ambiguity and 

 looseness in the use of this word " type," which it would be 

 well to avoid. Properly the type of a species is the species or 

 genus, or the full idea of it, which no one individual or species 

 may embody, which in the case of a group no single represen- 

 tative or member can fully exemplify. To apply the term to 

 a form which well exemplifies the essential characters of the 

 species or genus is quite natural, and hardly involves any 

 confusion. But the term is also used in a historical sense, 

 as referring to the particular form on which a species was 

 founded, or the species on which the genus was characterized 

 or which its founder had mainly in view, but which very often 

 proves not to be the best representative of the group, some- 

 times not even a fair one. Finally a particular specimen 

 which the original author described, or an authentic specimen, 

 is said to be a type, or a typical specimen ; and this De Candolle 

 objects to. But after all, such terms can hardly he held to a 

 single sense in technical any more than in ordinary language. 

 Something must be left for the context to determine. 



In drawing up the characters of groups, such especially as 

 orders and genera are exceptions or what we call exceptions to 

 be indicated in the character ; or shall this express only what 

 is generally true ? De Candolle discusses the question, but 

 leaves it, as must needs be, for practical judgment to determine. 

 On the one hand the point or the usefulness of a character is 

 blunted or dissipated by the intercalation of alternatives and 

 exceptions, yet characters must be somehow made to corre- 

 spond with the facts. The method of Bentham and Hooker, 

 of a separate specification of the principal known exceptions, 

 is commended. 



Should outlying or anomalous groups be incorporated with 

 the orders they most resemble, or be merely appended as 

 " genera affinia," and the like ? The latter was inevitable in 

 the earlier days of the natural system ; but increasing knowl- 

 edge, as well as considerations of symmetry and convenience, 

 more and more fix the place of these floating groups ; so that 

 their general incorporation into the orders by Bentham and 

 Hooker in the Genera Plantarum of our day is in the natural 



