Dear Darwin

I sent the 3 vols of DC this morning— Keep them as long as you please.²

Sinclair sailed a month ago duly crammed & truly interested in the Bee & Trefoil case of which he took notes—but by all means write him a note directed D^r Sinclair RN. Auckland New Zealand.—³ it will please him as he goes out mainly to give a year up to collecting in Nat Hist & is a steady going Enthusiast though unfortunately a very uneducated one. I wonder that you were not struck with the great Buckle—⁴ I was—all of a heap.—& quite echo your brothers opinion—that he is the damndest bore I ever met, & what is more, the most obtrusive & offensive one. I have ransacked my brains to remember his equal in vain—sure such an obnoxious dog will come to grief ere long.

As to my argument with him I felt doubled up altogether—the cool way in which he 3 times shifted his ground gave me the worst opinion of his unfairness & when he said “Ah—well—perhaps we have different ideas of what the Inductive & Deductive methods are”—I felt that I had got my belly-full & sneaked away as I should from a treacherous savage, looking over my shoulder to see if he followed. Frances hated him—cordially—as a woman can. This by no means interfered with our thorough enjoyment of the Wedgwoods party—but perhaps heightened it.

I had met the Farrers before at a small party & was taken with Mr F. before I saw his Seraphic wife. (I think it is seraphims that sing). ⁵

I will answer your query about big genera deliberately, in the affirmative & give examples. I have been thinking a great deal on amount of variability in great & small genera.—& find it exceedingly difficult to explain logically the practical reasons there are against Botanists making varieties of well marked species, ie. of small genera. Many of the small genera still kept up would never have been made at all, had the whole of the Natural Order as now known been known when those genera were made. EG. in Europe we have say 3 very different members of a large unknown Asiatic group of plants containing 100 species: of these 3, as many genera are made in Europe: but after getting all the 100 Asiatic species, though these show that the said 3 genera are naught, we do not therefore cancel them—but in 9 cases out of 10 we group the Asiatic species as best we can under the 3 European genera— A thousand unphilosophical reasons occur, of considerable (present practical) weight to cause us to keep up the said old genera—

We must never forget that Systematists have two very different ends to meet—

to provide a ready nomenclature without which the science cannot advance, & which we change as little as possible—& further we use every means to avoid even a necessary change—so important is it for all to get up the nomenclature & so bulky & complicated is this nomenclature.

To arrange the members of the vegetable Kingdom scientifically which is only done for the sake of scientific followers

Now we repeatedly find that to express our views scientifically we must break up the whole nomenclature, & rather than do this excessively, we confine ourselves to stating our views without acting upon them

In no respect do we sacrifice more to the utilitarian purpose of nomenclature, than in keeping up small bad genera.

Practically no one (except a few of us) hesitates to remove a very distinct species of an old genus, especially if its characters are constant, & it is an invariable plant, & to make of it a new genus—just because it is more unlike its 20 neighbours than they are unlike one another— The probabilities in this case are that the 20 are varieties of 8 or 10, & being variable have varieties made of themselves, whilst the 1 constant plant goes to a new genus—& is a small genus with no varieties.

Again, practically very few do up an old genus of one or a few well marked unvarying species especially if its generic name is a very familiar one. hence Amygdalus, Prunus, Cerasus—are kept up, though certainly not good genera in a scientific view of Rosaceæ. Few plants are more variable than Hawthorn—it is a small genus dismembered from Pyrus, but no British author makes varieties of it.

Genera in short are almost purely artificial as established in Botany.— some are objective like Salix & Rosa, ie. every ignoramus recognizes them & they are called natural genera—good genera—&c &c. others are subjective, they require a special knowledge of the order to which they belong to know them—ignorami do not recognise them. Such are the genera of Grasses Cruciferæ Umbelliferæ &c But between what the ignoramus does recognize & does not there is no limit: & the first-rate Botanist working upon a partial knowledge of a group is only in the position of an ignoramus after all—his two very distinct groups of an order are to him two genera; had he the whole species of the order he would never have recognized the groups at all, as groups.

This is a terrific screed

Ever yrs | J D Hooker