I have not been able sooner to acknolege the reciept of your letter of Dec. 24. which came to hand on the 5th. inst. and to decline availing myself of the offer you are so good as to make therein respecting the collection of the oaks of this country.   the nature of my occupations, and the constant absence from home which they have rendered necessary, have never permitted the idea of my publishing any work relating to that subject, or to make any collections of plants of any kind; and at the period of my retirement it will be too late to begin such undertakings. with my thanks therefore for the offer you have been pleased to make, accept my salutations & respects