Experiments on the Color Sense. 
259 
ner. Ten minutes more, and she seemed to have made up her 
mind, for she walked directly to her nest and entered it. 
The spider now had a lesson every day for a week, being 
forced out of her nest and to the other side of the box, and left 
to find her way back. She always went back to her eggs, stay¬ 
ing out sometimes only a few minutes and sometimes one or 
two hours. She took water but no food. 
August 13. The spider was taken from the box and the pa¬ 
pers around the false and the true nests were exchanged, the 
red being put back around the eggs, while the yellow was put 
around the cotton. This reversed the position that they had 
had since the last experiment. 
The spider was then put in at the edge of the yellow paper 
which she was now accustomed to seeing around her nest. She 
remained motionless, looking at the cotton for three minutes, 
and then approached it with her first legs raised. She had not 
taken this attitude before since the last experiment, having con¬ 
stantly passed and repassed the cotton nest surrounded by red 
paper without noticing it. She walked around the cotton with¬ 
out touching it, then left it and went toward the red paper. 
On reaching the edge she turned and went back to the yellow 
and went close to the cotton without raising her legs, and then 
went back to the edge of the red paper. After standing there 
a moment she returned to the yellow and walked all around the 
cotton, feeling of it with her first legs. She then went to an 
empty corner of the box where she remained for thirteen min¬ 
utes. At the end of this time she went to the yellow paper and 
took one more look at the cotton, and then turning to the red 
went on to it and into her nest. 
Xysticus ferox. We had expected that this species would be 
an especially convenient one for these experiments as instead of 
fastening its cocoon into some corner it places it upon a flat 
surface and then holds on to it without any covering for itself. 
We thought that circular bands of colored paper could be 
dropped so as to surround her, and could be changed from time 
to time very easily, but she was timid and easily disturbed, 
and deserted her eggs before the necessary lessons preliminary 
to the experiment were over. 
