80 UPLAND AND MEADOW. 



when wrens were tested. These immediately became 

 very angry, and finally, an over -excited house -wren 

 pitched headlong at the supposed interloper, with the 

 doubly fatal result of killing itself and breaking the 

 glass. Subsequently, taking a larger glass, that was 

 thick enough to withstand ordinary attacks by wrens or 

 larger birds, I placed it on the ground, and soon found 

 that it was supposed to be water. Chickens tried in 

 vain to drink, as did small wild birds ; and none seemed 

 to be surprised at seeing their own reflections. It would 

 seem, from this, that such reflection in water is a com- 

 mon occurrence, and they gave it no thought, but recog- 

 nized a difference when they found the glass in a per- 

 pendicular position, near their nests. Did they realize 

 that in this latter instance it could not be water? If so, 

 birds have gotten so far as to have some knowledge of 

 physics; which, after all, is not much to be wondered 

 at, when they are, all of them, excellent mechanics. 



Experiments of another character were as follows : I 

 placed a series of short pieces of woollen yarn, fastened 

 together at one end, near the tree containing a partly 

 constructed nest of a Baltimore oriole. These yarns 

 were red, yellow, purple, green, and gray. An equal 

 number of strands of each color were thus offered to the 

 orioles as building-materials. I purposely placed the 

 red and yellow strands on the outside of the tassel-shaped 

 mass, so that these would be first taken, if the color was 

 not objectionable. To my complete surprise, the gray 

 strands only were taken, until the nest was nearly fin- 

 ished, when a few of the purple and blue yarns were 

 used. Not a red, yellow, or green strand was disturbed. 



