In May two boys in town wrote to me to explain to them the meaning of the egg-shells, mostly those of robins, that were to be seen lying about on the ground here and there. I supposed every boy knew where most of these egg-shells came from. As soon as the young birds are out, the mother bird removes the fragments of shells from the nest, carrying them in her beak some distance, and dropping them here and there. All our song-birds, so far as I know, do this. Sometimes, however, these shells are dropped by blue jays after their contents have been swallowed. The jay will seize a robin's egg by thrusting his beak into it, and hurry off lest he be caught in the act by the owner. At a safe distance he will devour the contents at his leisure, and drop the shell. The robins, however, have more than once caught the jay in the act. He has the reputation among them of being a sneak thief. Many and many a time during the nesting season you may see a lot of robins mob a jay. The jay comes slyly prowling through the trees, looking for his favorite morsel, when he is discovered by a vigilant robin, who instantly rushes at him crying, "Thief! thief!" at the top of his voice. All the robins that have nests within hearing gather to the spot and join in the pursuit of the jay, screaming and scolding. The jay is hustled out of the tree in a hurry, and goes sneaking away with the robins at his heels. He is usually silent, like other thieves, but sometimes the birds make it so hot for him that he screams in anger and disgust. Of the smaller birds, like the vireos and warblers, the jay will devour the young. My little boy one day saw a jay sitting beside a nest in a tree, probably that of the red-eyed vireo, and coolly swallowing the just hatched young, while the parent birds were powerless to prevent him. They flew at him and snapped their beaks in his face, but he heeded them not. A robin would have knocked him off his feet at her first dive.