18441858] LARGE GENERA 107 



To J. D. Hooker. Letter 62 



Feb. 23rd [1858]. 



Will you think of some of the largest genera with which 

 you are well acquainted, and then suppose i of the species 

 utterly destroyed and unknown in the sections (as it were) as 

 much as possible in the centre of such great genera. Then 

 would the remaining i of the species, forming a few sections, 

 be, according to the general practice of average good Botanists, 

 ranked as distinct genera? Of course they would in that 

 case be closely related genera. The question, in fact, is, are 

 all the species in a gigantic genus kept together in that genus, 

 because they are really so very closely similar as to be 

 inseparable ? or is it because no chasms or boundaries can 

 be drawn separating the many species ? The question might 

 have been put for Orders. 



To J. D. Hooker. Letter 63 



Down, Feb. 9th [1858]. 



I should be very much obliged for your opinion on the en- 

 closed. You may remember in the three first vols. tabulated, 

 all orders went right except Labiatae. By the way, if by any 

 extraordinary chance you have not thrown away the scrap of 

 paper with former results, I wish you would return it, for I 

 have lost my copy, and I shall have all the division to do 

 again ; but do not hunt for it, for in any case I should have 

 gone over the calculation again. 



Now I have done the three other vols. You will see that 

 all species in the six vols. together go right, and likewise 

 all orders in the three last vols., except Verbenaceae. Is not 

 Verbenaceae very closely allied to Labiatae ? If so, one would 

 think that it was not mere chance, this coincidence. The species 

 in Labiatae and Verbenaceae together are between \ and \ 

 of all the species (15,645), which I have now tabulated. 



Now, bearing in mind the many local Floras which I have 

 tabulated (belting the whole northern hemisphere), and con- 

 sidering that they (and authors of D.C. Prodromus) would 

 probably take different degrees of care in recording varieties, 

 and the genera would be divided on different principles by 

 different men, etc., I am much surprised at the uniformity of 

 the result, and I am satisfied that there must be truth in the 



