[64]

[Letter not transcribed]

[64v]

295

Lathyrus

visiting the flowers, he assumes that on this one occasion they would have been intercrossed.) I have myself purposely made similar trials with the same result. I have said that although the varieties always come true, but yet as we shall presently see, that a perfectly characterised variety one of the five well-known varieties occasionally arisen from the seeds of another; and if there be no selection, as I was informed by the later Mr. Masters gives birth to another of the varieties, which exhibits all its usual characters. Owing to this curious fact, or to the darker-coloured varieties being the most productive, increase their increase, as I was informed by the late Mr Masters to the exclusion of the others, if there be no selection.)

(77) In order to ascertain what would be the effect of crossing two varieties, some flowers on the Purple sweet-pea, which has a dark reddish [text excised]

[Cross and self fertilisation, p. 153: "The case therefore of Lathyrus odoratus or the sweet-pea is curious, for in this country it seems invariably to fertilise itself. I conclude that this is so, as five varieties, differing greatly in the colour of their flowers but in no other respect, are commonly sold and come true; yet on inquiry from two great raisers of seed for sale, I find that they take no precautions to insure purity—the five varieties being habitually grown close together.† I have myself purposely made similar trials with the same result. Although the varieties always come true, yet, as we shall presently see, one of the five well-known varieties occasionally gives birth to another, which exhibits all its usual characters. Owing to this curious fact, and to the darker-coloured varieties being the most productive, these increase, to the exclusion of the others, as I was informed by the late Mr. Masters, if there be no selection.
† See Mr. W. Earley in 'Nature' 1872 page 242, to the same effect. He once, however, saw bees visiting the flowers, and supposed that on this occasion they would have been intercrossed.
In order to ascertain what would be the effect of crossing two varieties, some flowers on the Purple sweet-pea, which has a dark reddish-purple standard-petal with violet-coloured wing-petals and keel, were castrated whilst very young, and were fertilised with pollen of the Painted Lady."]