for evidences of nesting activity. R had not been heard singing and it was thought that he might be busy building. In less than one minute he came down from what appeared to be the exact spot and returned to it a few seconds later. Due to intervening branches and his quick, business-movements, I was unable to see if he car- ried anything. After this observation nothing was seen or heard of him or his mate during the rest of the day, although I explored the territory about 400 yards to the N.E., which is now much favored by them, and has innumerable superior nesting sites. Nest 11. Brownie occasionally added a wisp or two of soap-root lining; Nova did not help at all; in fact has not been seen to work on it at any time. Both took good care of the young ones, who are now digging quite energetically. April 17th. At 7:50 Rhody was not at Sta. 3, nor had he been heard. At 8:50, ditto. At this time Nova and Brownie were gathering soap-root fibre in large bundles for the nest and still attending to their brood. This is the stage of nest building where the female helps most: in fact, in the case of Nova, it may be the only time; furthermore, she may not help at all. Brownie continues to sing at intervals throughout the day, whereas Nova, aside from occasional scripping, is practically dumb. She has not been heard in full song more than once or twice this season. It is clear that, at this place at least, thrashers remain mated for more than one season. Both Greenie and Nova (with B) exemplify this. April 18th. to 20th. incl. Nothing has been seen of Rhody at this place, but about noon