PLATE I 
EXPLANATION OF FIGURES 
1 Young cuckoo on day of birth, and two eggs, which were hatched two and 
four days later, respectively. From nest no. 2 (fig. 9), August 1, 5 p. m. One-half 
natural size. 
2 Young cuckoo, shortly after birth, raising itself to support. Bird no. 3, 
nest no. 3 (table 6) ; born 12.45 p. m., July 20; photographed at 4. 30 p. m. Two- 
thirds natural size. 
3 The same bird hanging from second and third toes of zygodactyle foot. 
Photographed on same date, at same time, and same relative size. 
4 Cuckoo, seven days old, sitting on nest, with feathers partially erect. Bird 
no. 3, nest no. 1 (table 6), July 29. Would probably have left the nest earlier but 
for slight injury. 
