I fear that I am doing wrong by writing to you upon a subject with which I am not acquainted, but one of the friends of Mr Hensler a Swiss now in this City, extorted a promise from me that I would mention him to you with a view to his employment in surveying the Coast &c—I therefore beg leave to state to you that many circumstances which have occurred during his residence here, have made a strong impression in his favour, on the minds of many members of our Society; & if a person is wanted for the above mentioned purpose, I beg leave to suggest to you to enquire of Mr Patterson, who I believe has had a good opportunity of judging of his qualifications as well of those of another swiss Gentleman, also of this City, who has been engaged with him in the survey of Switzerland.
In my last I stated my belief that the head which you presented to the Society would appear to have belonged to a specie of Squirrel; in the course of my enquiries to ascertain the truth of this idea, I examined all the specimens of Rodentia or Glires which I could procure, & by that means discovered that it was the head of the Marmotte of Buffon or Ground Hog of this Country—All the Society are satisfied of this; & indeed there was but one single circumstance in which the heads differed. viz the length of the front teeth—in our specimen the teeth are so much curved that they allmost touch the roof of the Mouth, whereas in the recent specimens, the teeth are nearly of the length of those of the Rabbit or Squirrel, this difference is fully explained by a note in Edwards’ Gleanings of Natural History, which states that one of these Animals was sent from Maryland to Sir Hans Sloan, with whom it lived a long time in a state of the most perfect domestication, but in consequence of eating soft food, the upper four teeth grew so long, that they were obliged to break them, to keep the animal from starving. Dr Barton has been informed of a similar growth of Teeth in the Squirrel Your friend Stewarts idea respecting the residence of the Animal in caves was very correct.
with the best wishes I am most respectfully your obliged friend
C Wistar Junr.
DLC: Papers of Thomas Jefferson.