My dear Sir
Anytime when you happen to write to me, but not write on purpose, please tell me name of enclosed Fumaria or Corydalis— it grows in my garden in open air.— It exhibits a very little, pretty adaptation to Bees.—2 The long nectary alone secretes honey; & when Bees are sucking, they push off the hood over the pistil & stamens; & then the pistil & stamens (curved to side of nectary) are rubbed against Bee’s belly, & so cross would often be effected. As long as hood is kept pushed off the pistil & stamens, it keeps open, & when it springs back, it beautifully snaps together & again encloses the pistil & stamens.— Now if you push the opposite way, which Bees never do, as there is no nectar on that side, it is with difficulty that the hood can be pushed off the pistil & stamens, but when this is effected, the hood does not keep open, & so can never again enclose & protect the pistil & stamens.3 It is worth looking at fresh flower, & trying with a pin.—
In Dielytra, where nectar is on both sides, pistil is straight, & the hood can be pushed off both sides with equal facility, as I have seen Bees do.— Here is much cry & little wool!4
Yours very sincerely | C. Darwin
Please cite as “DCP-LETT-3499,” in Ɛpsilon: The Charles Darwin Collection accessed on