The first recorded correspondence between Treat and Darwin originates from 20 December 1871 in which Treat describes the fly-catching activities of Drosera, commonly known as sundew plants.
Treat and Darwin’s recorded correspondence extends over five years around the period of time when Darwin was researching, and then publishing, on carnivorous plants.
They predominantly discuss these plants in their correspondence (although not the only theme, they also discussed controlling sex in butterflies), and Treat openly critiqued Darwin’s hypotheses.
One notable exchange concerned the bladderwort plant, Utricularia clandestina.

Darwin’s teacher and mentor at Cambridge, John Stevens Henslow, had a clear understanding of the morphology of Utricularia (bladderwort) plants, but was not able to understand working mechanics of their traps.
Darwin incorrectly concluded that animals entered the traps by forcing their heads through the slit-like orifice with their heads serving as a wedge.
In a letter to Treat he informed her that this subject drove him ‘half-mad’.
Treat became deeply absorbed in this problem, researching intensively.
Through long hours of observing the trapping sequence under her microscope she realised that the hairs around the entrance to the trap were sensitive and part of the process by which Utricularia traps opened, contributing new knowledge on the range of microscopic animal prey caught in these traps and the digestive processes they were subjected to.
Treat described it as ‘these little bladders... in truth like so many stomachs, digesting and assimilating animal food’.
Darwin was so impressed with Treat’s work on carnivorous plants that he referenced her, both within the main text and in footnotes, throughout his publication Insectivorous Plants (1875).

By making such public affirmations of Treat’s scientific work, Darwin legitimized her role as a scientist, though this is not completely uncontested among historians .
Gianquitto’s opinion is, however, not reflected by all writers discussing Treat’s scientific identity’.
With the advent of the Internet, Treat's correspondence with Darwin has been analyzed in more detail.
The first recorded correspondence between Treat and Darwin originates from 20 December 1871 in which Treat describes the fly-catching activities of Drosera, commonly known as sundew plants. Treat and Darwin’s recorded correspondence extends over five years around the period of time when Darwin was researching, and then publishing, on carnivorous plants. They predominantly discuss these plants in their correspondence (although not the only theme, they also discussed controlling sex in butterflies), and Treat openly critiqued Darwin’s hypotheses. One notable exchange concerned the bladderwort plant, Utricularia clandestina.
Darwin’s teacher and mentor at Cambridge, John Stevens Henslow, had a clear understanding of the morphology of Utricularia (bladderwort) plants, but was not able to understand working mechanics of their traps. Darwin incorrectly concluded that animals entered the traps by forcing their heads through the slit-like orifice with their heads serving as a wedge. In a letter to Treat he informed her that this subject drove him ‘half-mad’. Treat became deeply absorbed in this problem, researching intensively. Through long hours of observing the trapping sequence under her microscope she realised that the hairs around the entrance to the trap were sensitive and part of the process by which Utricularia traps opened, contributing new knowledge on the range of microscopic animal prey caught in these traps and the digestive processes they were subjected to. Treat described it as ‘these little bladders... in truth like so many stomachs, digesting and assimilating animal food’. Darwin was so impressed with Treat’s work on carnivorous plants that he referenced her, both within the main text and in footnotes, throughout his publication Insectivorous Plants (1875).
By making such public affirmations of Treat’s scientific work, Darwin legitimized her role as a scientist, though this is not completely uncontested among historians . Gianquitto’s opinion is, however, not reflected by all writers discussing Treat’s scientific identity’. With the advent of the Internet, Treat's correspondence with Darwin has been analyzed in more detail.
Mary Treat