what does "I am, etc" mean?
I should now proceed to such birds as continue to sing after Midsummer, but, as they are rather numerous, they would exceed the bounds of this paper: besides, as this is now the season for remarking on that subject, I am willing to repeat my observations on some birds concerning the continuation of whose song I seem at present to have some doubt.
I am, etc.】

this is the last paragragh of a letter, I don't understand the Signed part, what does "I am, etc" mean?

Question

what does  "I am, etc" mean?
I should now proceed to such birds as continue to sing after Midsummer, but, as they are rather numerous, they would exceed the bounds of this paper: besides, as this is now the season for remarking on that subject, I am willing to repeat my observations on some birds concerning the continuation of whose song I seem at present to have some doubt.
I am, etc.】

this is the last paragragh of a letter, I don't understand the Signed part, what does  "I am, etc" mean?

Answer

I suspect it means the author is replacing the usual closing with "etc." At that time it would have been something longer  such as "I am your most humble and obedient servant."
http://en.wikipedia.org/wiki/Valediction

Answer

Is it an example letter? Maybe the letter was supposed to have another sentence/page?

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