My dear Sir

Very many thanks for the Primulas (& about common Primrose) which I received this morning & examined.² Only one was dimorphic: but I have every reason to suppose the others would have been so, had you possessed a greater number of plants.— P. Siberica, however, seems to differ from all other species in not being dimorphic.—³

I have been deeply grieved to hear about Prof.— Henslow—

Yours very sincerely | C. Darwin

As P. Siberica is apparently so exceptional, would you ask M^r Croker, if you have other plants, which come into flower to send me 2 or 3 flowers (not whole trusses) for examination, in order that I may see whether they present any incipient trace of dimorphism.—

But if your plants have been increased all by offsets from same original plant, it will be no use to send them. As the character is permanent by offsets.

I do not know whether I shall succeed in making out the meaning of the dimorphism; but I have not been idle, for I have made much above 100 crosses with the pollen of the different sizes.

The lot sent has been most interesting to me.— Pray thank M^r Croker—⁴

Do not trouble yourself to write if you can at any time send me other specimens of P. Siberica—