Sketch of the Life of the late Professor Edward Forbes. 45 



Geological Transactions, illustrated by the best plates of fossil 

 Invertebrata ever done in England. 



About this time he wrote on the connexion between the dis- 

 tribution of the existing Fauna and Flora of the British Isles, 

 and the geological changes which have affected their area. 



In 1 848 his admirable Monograph on the British Naked-eye 

 Medusse was published by the Ray Society. 



Subsequently appeared his Palseontological and Geological 

 Map, contributed to Johnston^s Physical Atlas ; and in 1850 he 

 completed, with Mr. Hanley, the splendid work on the ^ Natural 

 History of the British Mollusca and their Shells.^ 



His wonderful facility in all departments of science was due. 

 Hooker says, to the early age at which he acquired its rudiments, 

 and to the efficient practical training in systematic botany and 

 collecting which he received in Edinburgh ; to his quick percep- 

 tion of affinities ; to his philosophical views of morphology, dis- 

 tribution, structure, functions, and the mutual relations of all 

 these ; to his mind being richly stored with the literature of the 

 sciences ; to the wide experience obtained during his travels ; and, 

 finally, to that heaven-given power of generalization and abstrac- 

 tion which he so eminently possessed. 



In 1848 he married a daughter of the late General Sir C. 

 Ashworth. It is curious to notice, that during that year four 

 were married out of the ten who met to institute the Botanical 

 Society. 



In 1852 he published some valuable observations in regard 

 to genera and species, in reference to which I received the follow- 

 ing letter : — 



" Jermyii Street, 19th June, 1852. 

 "My dear Balfour, 



** The paper I sent you is a brief abstract of a long lecture*. It 

 contains, in fact, only the table of contents, without the illustrations 

 and comments : hence its obscurity. .. ^■>^^> 



"My notions about genus are these : — 'i[3n s. to 



" What we call class, order, family, genus, are all only so many 

 names for genera, of various degrees of extent. It is in this sense I 

 use the word genus in my lectures. Technically, a genus is a group 

 to which a name (as Ribes) is applied ; but essentially, Exogens, 

 Ranunculacece, Ranunculus, are genera of different degrees. 



" Now, one of the chief arguments in favour of the naturalness of 

 genera (or groups, if you like), is that derived from the fact that 

 many genera can be shown to be centralized in definite geographical 

 areas {Erica, for example) ; i> e. we find the species gathered all, or 

 mostly, within an area, which has some one point where the maximum 

 number of species is developed. 



" But, in geographical space, we not unfrequently find that the 

 same genus may have two or more areas, within each of which this 

 * [Inserted in the ' Annals ' for July, 1852.] 



