The Life and Letters-1 [203]
points better adapted for comparison with Europe than that of the whole of North America. You ask me to state definitely some of the points on which I much wish for information; but I really hardly can, for they are so vague; and I rather wish to see what results will come out from comparisons, than have as yet defined objects. I presume that, like other botanists, you would give, for your area, the proportion (leaving out introduced plants) to the whole of the great leading families: this is one point I had intended (and, indeed, have done roughly) to tabulate from your book, but of course I could have done it only VERY IMPERFECTLY. I should also, of course, have ascertained the proportion, to the whole Flora, of the European plants (leaving out introduced) AND OF THE SEPARATE GREAT FAMILIES, in order to speculate on means of transportal. By the way, I ventured to send a few days ago a copy of the "Gardeners' Chronicle" with a short report by me of some trifling experiments which I have been trying on the power of seeds to withstand sea water. I do not know whether it has struck you, but it has me, that it would be advisable for botanists to give in WHOLE NUMBERS, as well as in the lowest fraction, the proportional numbers of the families, thus I make out from your Manual that of the INDIGENOUS plants the proportion of the Umbelliferae are 36/1798 = 1/49; for, without one knows the WHOLE numbers, one cannot judge how really close the numbers of the plants of the same family are in two distant countries; but very likely you may think this superfluous. Mentioning these proportional numbers, I may give you an instance of the sort of points, and how vague and futile they often are, which I ATTEMPT to work out...; reflecting on R. Brown's and Hooker's remark, that near identity of proportional numbers of the great families in two countries, shows probably that they were once continuously united, I thought I would calculate the proportions of, for instance, the INTRODUCED Compositae in Great Britain to all the introduced 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 FULL BELIEF that you will believe me that I have not the folly and presumption to hope for a second that you will give it, without you can with very little trouble. The point can at present interest no one but myself, which makes the case wholly different from geographical distribution. The only way in which, I think, you possibly
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 FULL BELIEF that you will believe me that I have not the folly and presumption to hope for a second that you will give it, without you can with very little trouble. The point can at present interest no one but myself, which makes the case wholly different from geographical distribution. The only way in which, I think, you possibly