Esteemed Sir!

I beg you to forgive the long delay in replying to your recent letter. You see, I had hoped to be able to give you more precise and more complete information regarding the questions that you deigned put to me.² Most unfortunately I could gather only very little information.

The Lathyrus odoratus is a plant that in central Italy is cultivated hardly at all and researched only a little, above all in recent years, because it has been greatly attacked by Oidium.³ Among the gardeners of Florence the view prevails that crossing between one individual race and another may occur, and that consequently the varieties cannot be preserved, unless one sows them separately.⁴ A very experienced plant breeder, a certain Sig. Paolo Baroni,⁵ assured me that after many successive years during which they had not been attended to, there was always the same variety in the same flower bed; he firmly believes, however, that it did not propagate there through seeds, but rather through perennial root buds (possibly through these little tubercules one can see in the roots of many Lathyrus).

Regarding Phaseolus multiflorus, then, the same gardener is absolutely convinced that in order to obtain the pure variety one must above all prevent crossing by means of insects.⁶

Regarding Pisum sativum, over here this plant is grown only in kitchen gardens and in the country, as foodstuff. There are quite a few varieties of it, and they generally remain pure because they are mostly grown in great separate masses. Apart from that, I have never observed insects on Pisum, and I therefore believe that in the absence of insects homogamic fertilisation is perfectly possible.⁷

I thank you for the courteous words about myself in your letter. To receive encouragement from such an authority is a great comfort to me; all the more so since far too often I see my ideas find critics who strike me as less fair. Most recently, for example, I received a note by G. Bentham on composites, in which I suffered fairly unfounded criticism. Either he has not understood the force of my argument, or he must have given my work on Artemisiaceae a too superficial reading.⁸ I believe I owe him a response, not on my account but for the principles that I uphold. Scientifically speaking we find ourselves in a nasty crisis these days; there is this whole old school here, which consists entirely of people who lack the courage fully to accept the doctrine of the transformation of organisms. Now for me, this doctrine is factual truth, not just a hypothesis. Well, then we must apply it to taxonomy. But how could the taxonomists of the ancient school ever bow to the new forms of genealogical taxonomy?

I have received D^r. H. Müller’s book.⁹ It is very valuable in many respects, and it surely must serve as the starting point for numerous investigations that must be undertaken in the same direction. Having said that, I don’t find myself wholly in agreement with quite a number of fundamental points in it. H. Müller, with truly Germanic patience and precision, has counted the visits of insects, but he has not weighed them. As a result, he and I must differ on many points. For example, according to your observations and mine, clover flowers are designed exclusively for bees (it is a melittophilous plant);¹⁰ by accident, however, a butterfly might land on it; now, such a visit H. Müller will count strictly, while I would not make anything of it, since I would regard it as an accident without the slightest function. Apart from this, the book seems to me very useful to me and conscientious in the highest degree.

Most distinguished man, allow me to assure you of my most profound esteem and regard | Your most devoted disciple | Federico Delpino