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92 THE CONDOR Vol. XXII 
The young gained in size and strength rapidly. After they were several 
days old the male would sing from the tree as before, then fly direct to the 
nest and perching on the brim, would sing as if he would burst his 
throat. On one occasion a male Cassin Purple Finch seemed to share his joy, 
and, alighting on the singing tree, joined in and sang his best. The same inci- 
dent occurred again when the young were a week old, but this time the male 
vireo seemed to resent the intrusion and drove the finch away in a hurry, chas- 
ing him some distance. 
When the young were five days old, I noticed the male vireo looking into 
the nest after each feeding, and on investigating found one of the young dead 
in the bottom of the nest. I at once proceeded to remove the remains, and in 
so doing became aware of the advantage of horsehair woven in the nest lining. 
Fig. 24. YOUNG VIREOS, FIVE DAYS OLD. 
The young bird’s claws were closed tightly over several strands, and the inter1- 
or of the structure was considerably torn up before I managed to remove the 
dead bird. To all appearances the young bird had been dead but a short time, 
but it was infested with a number of large maggots and was in such a condition : 
that I made no effort to save it for later examination. I kept close watch of 
the young from then on, and two days later another showed signs of weakness. 
I failed to find any signs of maggot infestation, and the weakling began to im- 
prove slowly but was much smaller than the two others. 
The nest was kept very clean, both parents assisting in the task. At the 
age of nine days the eyes of the two stronger young were open, but the weak- 
ling was several days later in receiving its sight. In securing food for the 
young the female gathered much larger insects than the male, often coming in 
