Letter icon
Letter 9853

Treat, Mary to Darwin, C. R.

11 Feb 1875

    Summary Add

  • +

    Structure of Utricularia; its resemblance to an animal vascular system.


Vineland, N.J.

Feb. 11, 1875.

Dear Mr. Darwin,

Some weeks ago I obtained from the ponds, simply, the long white stems of Utricularia. Freezing had divested them of all leaf stems. Very soon the new branches began to make their appearance, and I found, that the species that I am observing, is perfectly circinate—when the branch is wholly unrolled that is the end of its growth. These branches send off secondary branches, and then again divide and sub-divide, and with the bladders scattered among the leaves and branches, it takes but a little stretch of the imagination to make this plant equal the animal vascular system.

Look at some of the flukes—for instance,

Amphistoma conicum, the vascular system of which, under the microscope, looks very much as this plant appears to the naked eye.

Yours gratefully | Mary Treat.

    Footnotes Add

  • +
    f1 9853.f1
    This letter is not yet published in the edition of The correspondence of Charles Darwin; it is due to appear in volume 23. The text is being made available here ahead of print publication as part of the `Darwin and Gender' project funded by The Bonita Trust.
Maximized view Print letter