Thus, if a Wren build in a haystack, the front of the nest is generally composed of the hay from the stack; if it be built in a bush by the side of a river, and (which is frequently the case) below flood mark, it is generally covered on the outside with the rubbish which has been left there by the flood; and if it build in a mossy stump, the front of the nest is composed of the dark- coloured moss which grows there. (May 22, 1832.) Along with my last letter, I sent some Wrens' nests lined with feathers, and I could easily have increased them to a dozen of the same sort, only I did not wish to deprive so many of my little favourites of their eggs and young. Every day convinces me more decidedly, that I am right both with regard to the lining of the Wrens' nests, and as to the cock-nests also. The nests I sent you will prove the former, and I know of at least twenty instances of the latter, in nests which I have known of all through the spring, from April to the present time, which have remained in the same unfinished state, although they are not forsaken, as I have found the birds in them, in several instances, when I have examined them. I found one of these nests on the 10th of April, under a bank on the side of the river; and I examined it repeatedly through April and May, and always found it in the same state, although there was always a pair of Wrens about, and I could find no other nest; yet I am sure there was another, for in the beginning of this month (June) there were some young Wrens, which had evidently only just come out of the nest; and there were only two or three bushes grew thereabouts, so that it is not probable they had come from any other quarter, but the bushes were filled with dead leaves, and other rubbish brought down by the flood. However, when I heard them, I looked out for another nest, as I believe (notwithstanding what Montagu says, that there are few birds, if any, that would produce a second lot of eggs if the first were unmolested) that most of the small birds which are early breeders build a second time the same year, even when they succeed in rearing the first brood. I have had proof of this (if anything can be considered proof, except marking the birds), in the Throstle, the Blackbird, the Wren, the Redbreast, and the Hedge Sparrow, whose second nests may be found contiguous to the first; and in point of time, this always happens just when the first brood have left the nest. The cock-bird, too, who had been silent whilst his young were unfledged, begins to sing again, and throwing off the anxious and care-beset manners of a parent, again assumes that of a bridegroom. But to return to Wrens' nests. I found one within ten yards of the one I had known of since the 10th of April, lined, and ready for an egg. As I was anxious to prove what I had so long believed, I pulled out this nest, thinking that the old bird was ready for laying a second lot of eggs; and that when I had destroyed this, as she had no other nest