A colour base, R.
A colour developer, C.
A purple factor, B.
A light wing factor, L.
A factor for intense colour, I.
On this notation our six coloured forms are:—
| (1) Purple bicolor | CRBLI.[[6]] |
| (2) Deep purple | CRBlI. |
| (3) Picotee | CRBLi or CRBli. |
| (4) Red bicolor ( = Painted Lady) | CRbLI. |
| (5) Deep red ( = Miss Hunt) | CRblI. |
| (6) Tinged white | CRbLi or CRbli. |
It will be noticed in this series that the various coloured
forms can be expressed by the omission of one or more factors from the purple bicolor of the wild type. With the complete omission of each factor a new colour type results, and it is difficult to resist the inference that the various cultivated forms of the sweet pea have arisen from the wild by some process of this kind. Such a view tallies with what we know of the behaviour of the wild form when crossed by any of the garden varieties. Wherever such crossing has been made the form of the hybrid has been that of the wild, thus supporting the view that the wild contains a complete set of all the differentiating factors which are to be found in the sweet pea.
Moreover, this view is in harmony with such historical evidence as is to be gleaned from botanical literature, and from old seedsmen's catalogues. The wild sweet pea first reached England in 1699, having been sent from Sicily by the monk Franciscus Cupani as a present to a certain Dr. Uvedale in the county of Middlesex. Somewhat later we hear of two new varieties, the red bicolor, or Painted Lady, and the white, each of which may be regarded as having "sported" from the wild purple by the omission of the purple factor, or of one of the two colour factors. In 1793 we find a seedsman offering also what he called black and scarlet varieties. It is probable that these were our deep purple and Miss Hunt varieties, and that somewhere about this time the factor for the