From John Scott [26 July – 2 August 1863]1
[Royal Botanic Garden, Edinburgh] – of individual sterility in Orchids. I have unfortunately failed in giving illustrations from genera distinct from those mentioned in my paper.2 This would have enhanced their interest; my experiments are so much limited here from want of subjects; our orchid collection being exceedingly poor.3
I can give you no information whatever as to origin of our Red & White Primroses.4 I have asked several old and experienced growers as to this: I find that all agree in regarding them as varieties of the common yellow; but, none can affirm that he has raised either from a perfectly pure yellow primrose. It is possible they may have such an origin as you suspect. If I be permitted, however, to lay any stress upon my experiments, they appear to me somewhat opposed to this.5 Thus though both varieties manifest curious idiosyncrasies in the production of seed when fertilised with own-pollen, individuals of both, nevertheless do as I have proved, occasionally produce seed. Hence if we admit them to be crosses; or hybrids between cowslips & primroses; ought we not naturally to look for an increased fertility from conjunctions with either of their presumed parents? This not being the case I had concluded before you had suggested the above that they were truly & simply modified descendants of the common yellow primrose. Since I have procured seeds from them, however, there are hopes for enlightenments on this. Perhaps you would like to try results. I therefore enclose a few seeds from both.6 I am sorry that I had no more by me, having sown all as I gathered them to economise time in the elicitation of evidence. One of the packets of Red you will observe queried; this may chance to be from the White variety; having neglected to name when I gathered contents: you may rely on their being from one or other of same however. I have only a single capsule left—certainly—sowed from the White variety likewise enclosed: I will send young plants, however, if I succeed in raising them.
I enclose also a few self-fertilised seeds of my equal stamened & styled Cowslip: perhaps you will like to see their results likewise.7 The great self-fertility of this plant conjoined with the high degree of sterility from unions with the other forms has surprised me much.
I am greatly obliged for your interesting tables on crosses between Cowslips & primroses.8 I was much struck with results of the crosses between long-styled Cowslips & Primroses. These eight flowers heteromorphicaly crossed produced no seeds, while from the same number of homomorphic crosses I had three capsules, containing respectively 17, 10 & 6 seeds: they—the seeds—were all—seeds— smaller than usual. I have sown them, however & we will see how they germinate. Is it not singular how the homomorphic should so exceed the heteromorphic?9 In your reciprocal cross—Primrose female—I see the heteromorphic cross is again abortive! Again how singularly productive your short-styled crosses are!10 The average production per capsule of my heteromorphic unions with White Primroses is about 21 seeds: the homomorphic about 13. I here refer to unions with own-pollen—
I really do not think that there is any fear from imperfect castration when insects are guarded against. I have at least always found as you say when these plants were so protected that no seed was produced even when the anthers were all allowed to remain.11
The plants of Linum Lewisii, with us have all turned out L. Libericum which has provoked me much.12 But, I have now got one plant which I am satisfied from description in Bot. Mag. is really L. Lewisii.13 But though I have watched every flower, there is no variation, all are short-styled. I have just had a note from a friend,14 however to call and see a plant of it which he informs me is producing in general short-styled flower, with others—occasionally sta. & sty. equal. This I will call and see. I trust it may prove so. I have looked over the specimens in the Herbaria here but they contain few specimens of it: they exhibit no traces however, of Planchon’s trimorphic characteristics15 Have you had any confirmatory evidence? Have you seen the Linum Mongynum, a dimorphic species? I find a long-styled plant of this singularly productive, and there is no short-styled plant near, indeed I have only seen dried specimens of the latter. The majority of the capsules produced by the former contained 10 apparently good seed—& this is the full number that it can possibly produce.
I am kept very busy at present; so pray excuse my hurried scrawl.
I remain | Sir | Yours very respectfully | J. Scott
His orchid paper limited because he does not give illustrations from distinct genera.
Discusses the self- and cross-fertility of coloured primrose varieties. Thanks CD for tables of unpublished Primula work.
Please cite as
Darwin Correspondence Project, “Letter no. 4175,” accessed on 26 October 2016, http://www.darwinproject.ac.uk/DCP-LETT-4175