Transactions of the Horticultural Society 5: 234-237 (1824)
XXVII. On the Variation in the Colour of Peas, occasioned by Cross Impregnation.
In a Letter to the Secretary.

Read October 15, 1822.


LIVING retired in the country, and having a taste for gardening, I have been for some years past endeavouring to raise new varieties of vegetables. A gentleman in the neighbourhood, seeing some of the fruits of my labours, put into my hands the Transactions of your Society: this was like the rising sun after the dawn, and I was enabled to see, not only how to do my work better, but that some things which occupied my attention had by others been already accomplished.

I have raised some new varieties of Peas, and as one of these appears to be at least a singular production, and finding very little on this subject in your volumes, I am tempted to give you a description of it, accompanied with a few observations.

*I have not been able to ascertain with certainty the names by which the two parent Peas are usually known by gardeners and seedsmen; but l believe that the Prolific Pea, which was the female parent of the new variety, is the Blue Prussian, and the dwarf Pea which was its male parent, the Dwarf Spanish.

In the summer of 1820, I deprived some blossoms of the Prolific blue of their stamina, and the next day applied the pollen of a dwarf Pea, and of which impregnation I obtained three pods of seeds.* In the following spring, when these were opened, in order to sow the seed, I found, to my great surprise, that the colour of the Peas, instead of being a deep blue, like their female parent, was of a yellowish white, like the male. Towards the end of the summer I was equally surprised to find that these white seeds had produced some pods with all blue, some with all white, and many with both blue and white Peas in the same pod.

Last spring, I separated all the blue Peas from the white, and sowed each colour in separate rows; and I now find that the blue produce only blue, while the white seeds yield some pods with all white, and some with both blue and white Peas intermixed.

The edible qualities of this Pea I have not tried, having but few. It grows two or two feet and a half high, and attains maturity about the same time with its blue parent, which it much resembles, and unfolds a large, deep green rich foliage, superior to any I have seen. It seems to require a greater depth and richness of soil than other sorts, or than I have given it.

*Horticultural Society's Transactions, Vol. I. page 105.

Should this new variety of Pea neither possess superior merit, nor be deemed singular in its bi-coloured produce, yet there is, I conceive, something in its history that will emit a ray of physiological light, or at least militate against an opinion held by Mr. SALISBURY, who, in his remarks on the anomaly of the Peach and Nectarines growing on the same branch, says,* "I have not a doubt of the important consequences which ensue, when the stigma of one plant imbibes pollen belonging to another, but these are only manifested in the succeeding generation."

That this is incorrect, is not here "determined by a more able physiologist," but by the above statement—by the above fact; for the effect was strikingly evident in the seed, which was changed by the impregnation from a deep blue to a yellowish white. And if the seed undergoes such a change, why may not the fruit? It is more than probable that it does; but, the change not being so conspicuous as the difference between blue and white, it has escaped observation. Perhaps the most effectual way to unravel the mystery of the anomaly, would be to impregnate a considerable number of Peach blossoms with the pollen of the Nectarine, and to examine minutely if any change succeeded in the fruit.

If this communication should be thought worthy to appear in your Transactions, I trust Mr. SALISBURY will excuse an humble attempt to reflect a little light on an obscure part of a science in which he himself is so luminous.

I am, Sir,
Yours respectfully,
Hatherleigh, Devonshire,
October 5, 1822.

Note by the Secretary.

*See observations on the accidental intermixture of character in certain fruits, at page 63 of the present Volume.

Previous to the receipt of the above communication, one on the same subject was transmitted by ALEXANDER SETON, Esq: and read at the Meeting of the Society on the 20th of August, 1822. Mr. SETON had happened to make a similar experiment, by impregnating the flowers of the Dwarf Imperial, a well known green variety of the Pea, with the pollen of a white free growing variety. Of the flowers so treated one only produced a pod, and it contained four Peas, which did not differ in appearance from the others of the female parent. It thus appears from the different results in this stage of the experiments made by Mr. GOSS and Mr. SETON, that the appearance of the fruit in the first instance is sometimes affected by extraneous impregnation, and sometimes not; the impregnation being effectual, as it was proved to have been, by the progeny in both of these instances, and it seems desirable that this interesting point, on which so much difference of opinion has arisen,* partly from observation, and partly from analogical reasoning, should be subjected to further experiment.

The plants which grew from the four Peas obtained by Mr. SETON, seemed to partake of the nature of both parents, being taller and more diffuse than the Dwarf Imperial, and less so than the male white parent; but the pods resembled those of the former, being short, and having but few Peas in each. On their ripening it was found that instead of their containing Peas like those of either parent, or of an appearance between the two, almost everyone of them had some Peas of the full green colour of the Dwarf Imperial, and others of the whitish colour of that with which it had been impregnated mixed indiscriminately and in undefined numbers; they were all completely either of one colour or the other, none of them having an intermediate tint, as Mr. SETON had expected. The representation of one of the pods in Plate IX. Fig. 1. conveys a very perfect idea of its appearance.

See Knight's comments

CybeRose note: The so-called "blue peas" are not blue. They have green cotyledons that appear bluish (or grey) when seen through the white seed-coat. For example, the Blue Prussian pea was also called "Green Prussian".