plants, and the result was, 10/92 = 1/9.2. In our ABORIGINAL or indigenous flora the proportion is 1/10; and in many other cases I found an equally striking correspondence. I then took your Manual, and worked out the same question; here I find in the Compositae an almost equally striking correspondence, viz. 24/206 = 1/8 in the introduced plants, and 223/1798 = 1/8 in the indigenous; but when I came to the other families I found the proportion entirely different, showing that the coincidences in the British Flora were probably accidental!
You will, I presume, give the proportion of the species to the genera, i.e., show on an average how many species each genus contains; though I have done this for myself.
If it would not be too troublesome, do you not think it would be very interesting, and give a very good idea of your Flora, to divide the species into three groups, viz., (a) species common to the old world, stating numbers common to Europe and Asia; (b) indigenous species, but belonging to genera found in the old world; and (c) species belonging to genera confined to America or the New World. To make (according to my ideas) perfection perfect, one ought to be told whether there are other cases, like Erica, of genera common in Europe or in Old World not found in your area. But honestly I feel that it is quite ridiculous my writing to you at such length on the subject; but, as you have asked me, I do it gratefully, and write to you as I should to Hooker, who often laughs at me unmercifully, and I am sure you have better reason to do so.
There is one point on which I am MOST anxious for information, and I mention it with the greatest hesitation, and only in the