I must tell you that the Scientific Association is invited to meet at San Francisco, California, next summer; and that we have fixed the meeting there conditionally, that is, in case the Californians care enough for our presence to transport a certain number of our representative men free of cost, or nearly so, across the wide continent. If not, we are to meet on the northern part of the Mississippi,--at Dubuque, Iowa, far enough west in all conscience, but a place from which we may easily reach the Falls of St. Anthony and Lake Superior. I must needs attend, as I shall have a retiring address to deliver. And though I can ill spare the time or afford the expense, yet Mrs. Gray and I are longing to see California. What say you and Mrs. Church about joining us for your next summer’s vacation? The mountains which form the sides of the Yosemite Valley will hardly offer as many kinds of flowers as the alpine turf of the Riffelberg, but they may be more novel to you....
On December 15, 1871, Dr. Gray wrote to President Eliot, after describing formally the completion of the new buildings, and something of the history and arrangement of the department, the following letter:
... I beg to add, for your consideration and that of the corporation, a few words of a personal character.
With the present academic year I shall have completed thirty years of service in the professorial chair to which I was called in the spring of 1842. The Garden, which had been under no professorial care for years, and which has since had a long and hard struggle for existence, the conservatories, the herbarium and its library, both steadily increasing, and now the lecture-room, laboratory, etc., make up an establishment which has grown by degrees into one which requires much time, care, and anxiety to administer, and for which I have now done the main part of what could be expected of me or any one man. The experience of the last and the present year clearly shows me that the work of instruction, steadily increasing in its demands under the present system, weighted more and more with the load of administration, is more than I can carry on. I have some warnings, besides, of the increase of years, which I ought to consider; and I definitively propose to lay down, at the close of the present academic year, as large a part of this load as I possibly can without serious prejudice to this department and this establishment. I suppose that either the duties of instruction or of administration, beyond that of the herbarium, must be entirely surrendered. If I can be spared, and if what I could do for the herbarium could be reckoned an equivalent for rent of the house I reside in, I should crave to resign both the charge of the Garden and of the professorship. There is reason to think that the time is at hand when changes such as are here suggested may be propitiously made.