Dec. 3rd. Nesting reflex? The adults continue friendly, occasionally gathering nesting material, carrying it toward, and sometimes up into, the old oak, which seems to be the focal point of their interest. (This is the tree in which they built their nest No.1). There has been little, if any, noticeable change in the young thrasher, other than that he seems to be getting stronger. Dec. 4th. metal Temperature controlled quarters for S. I rigged up a box containing a tray under which were placed two 40 watt lamps. The box is lined with heat-insulating material. In the upper compartment I placed a bi-metallic thermostatic arrangement which I made some time ago for another purpose. This may be regulated to maintain any desired temperature above the tray. On the floor of the tray is placed woolen fabric and in this arrangement the young thrasher is installed (when he is confined). The effect of the tray is to give what the plant propagators call "bottom heat", with more moderate temperature in the compartment above. The upper compartment is partly closed with a cloth, and the lamps below are so placed that the bird has his option as to temperature, light, etc. over a considerable range. When released in the cloister he is given a fibre door-mat on of which which he can play about and amongst the standing bristles he can dig. Dec. 5th. At 9 A.M. I went to the glade, Greenie being the first to answer my call by scripping loudly. Brownie came without comment until he jumped up to my knee, then he began to talk. After eating, Greenie prospected about for twigs, then went up into the old oak and examined various prospective building sites, one of which was old No. 1 location. B gathered and dropped soap-root fibres. G looks for nest site. Much undersong. There has been no full song for some time, but under-song is frequent, B chiefly and for long periods at a time. Audibility, say,