I think it was in the autumn of 1836 that the Lyceum of Natural History, New York, having with a great effort erected their hall, on Broadway just below Prince Street, I was appointed curator; had a room for my use, some light pay, proportioned to light duties, and this was my home for a year or two. There I wrote my papers, “Remarks on the Structure and Affinities of the Ceratophyllaceæ” (which dates February 20, 1837),--not a very wise production, and some of the observations are incorrect; also the better paper, really rather good, “Melanthacearum Americæ Septentrionalis Revisio,” published in 1837. Dr. Torrey had planned the “Flora of North America,” but had not made much solid progress in it. I, having time on my hands, took hold to work up in a preliminary way some of the earlier orders for his use. This was to pass the time for a while, for in the summer of 1836 I was appointed botanist to a great South Pacific exploring expedition, which met with all manner of delays in fitting out, changes in commanders, etc., until finally, in the spring of 1838, Lieutenant Wilkes was appointed to the command, the number and size of the vessels cut down, and the scientific corps more or less diminished. The assistant botanist, William Rich, an appointment of the Secretary of the Navy, was to be left out. I resigned in his favor, having been about that time appointed professor of natural history in the newly chartered University of Michigan. As I had thus far done fully half the work, Dr. Torrey invited me to be joint author in “Flora of North America.” The first part was printed and issued in July, the second in October, 1838, at our joint expense, my share being contributed from the pay I had been receiving while waiting orders as botanist of the exploring expedition.