Dear Professor Darwin.

I and a young man named Corbin who is a devoted Naturalist have made a number of experiments on the Utricularia in the manner you requested, and we conclude that the bladders are in no uniform position in the water.¹ We examined them as they floated in their natural position and the valve is turned in various directions.

We then examined them with regard to their age and here again we could find no uniform position— In the younger stage of growth however they were more usually with the narrow valve turned upwards, in mid-growth (when the air bubble seems most conspicuous) they are generally flat and later on hedgehog-like turned downwards, but I do not think these positions are uniform—

I send you some plants of Utricularia, some smaller ones I got from clearer water and they were partially sunk into the mud.²

I am however afraid that they will have been too much injured by being out of the water to be of much use to you.

Your’s very truly | H. M. Wilkinson

Aug^t. 5. 1874.