Dear Sir,

I have to thank you for your kind remembrance in sending me a copy of your work on cross-fertilisation, which I have read with much interest.¹ The increased vigour of the crossed progeny is very striking. I have some very striking examples of it in crosses between certain varieties of the opium poppy. In three cases they are indeed surprising   The parent forms rarely exceeding 3$\frac{1}{2}$ feet in height, whereas the mongrel progeny is from five to six feet in height with leaves proportionately increased in size and general grossness of habit. I shall this season when the progeny attain maturity make careful measurements and weighments of all, as I am sure they will interest you. It is to be observed however that we have no corresponding increase of the reproductive organs, either as regards size or fertility.— You will find a cursory notice of some of these varieties in a little work on opium Husbandry which I have just received from the printer. It is unfortunately too late to send you a copy of it by this mail, but I shall do so by the following.²

I am carrying out the experiments you suggested with the varieties of our opium poppy.³ I have already many curious results on the simple intercrossing of varieties, but it did not occur to me to try the mixed pollen. This I am now doing: following out with care your directions.— I have been and still am greatly surprised at the none natural intercrossing of the various varieties grown here on a large scale and on adjoining plots.— I have been this year carefully watching them for insects, but though just now I have many acres around my house in full flower, the all but utter absence of insect life amongst them is most striking, and certainly they are so far as I have observed here and in the opium districts generally haunted by none.

I have also attended to them during the night, and find two species of Noctua⁴ not infrequent, but in no instance have I observed them visiting the flowers: these as you are well aware close regularly every night, and could indeed with difficulty be entered by such insects. There appearance amongst the poppy is easily explained: the larvæ feeding on the young plants and proving most destructive pests. It is rather a striking instance of a plant with large flowers depending on the wind for cross-fertilisation. Each variety must needs have a prepotent pollen, seeing as I have observed we have no natural intercrossing of the varieties. This however I shall fully test this season.

I much regret that your letter on Lagerstrœmia did not reach me in Calcutta but had been kept along with others until my return here.⁵ I at once wrote to Dr. King,⁶ and asked him to look over the fossils in the herbarium, or if he had not time to spare to send them to me here. He promised to look over them himself on an early day, and afford me all the information you asked for. I know he has lately been very busy with the examinations of students, and this probably is the cause of his not yet having complied with the request. I shall remind him however. I regret that I am so busy with opium duties just now, that I cannot run down to Calcutta and examine the plants myself.

I am also making a careful series of observations on barometric pressure as influencing the exudation of the opium juices. You will find this briefly treated in the work I am now sending you and an explanation of the phenomena of cyclosis.⁷ By an early mail, I will send a paper for the Linn. Society, on the circulation of the sap and other correlated phenomena.⁸ It remains to be seen how my views may be received, as I have nobody here with whom I can discuss them.

In referring to Lagerstrœmia, I quite forget to say that the Common Flax,⁹ plant which is largely cultivated here for its seeds is perfectly hermaphrodite: pistils of the long-styled and stamens of the short-styled form: it is perfectly self-fertile and scarcely if at all, in so far as I have seen visited by insects. I will send specimens along with the Lagerstroemia flowers.

I remain | Dear Sir | Yours truly | John Scott