INSTINCT AND INTELLIGENCE IN BIRDS 
131 
GROWTH-RECORDS IN CEDARBIRDS AND CuUCKoos, FROM HaTcHING TO FLIGHT, 
OR CLIMBING STAGES 



li oA 

13 
Day. 0 1 2 3 5 6 | YT |e 8 9 | mW | 1) 2 Lae 
a ee ee rar a | | 
Cedarbird. Foal “OTE ee ee 
1) 2.41 | 5.00) 7.92)10.44)17.28)23.04 26.64 29.16 34.56 39.24/39.60 40.32 41.04. — | — oe 
Wt. in J 2) 2.41| 3.42) 6.48) 7.92/11,52/17.28|20.16 24.12 28.08 30.90/32.76)33.48)37.44 36.36 34.20 36.72 
g. 3) 2.41) 3.96] 6.66) 8.28)12.24/17.64) 20.52) 21.72 27.72/31.68)33.84 33.12/36.00 37.44 35.28 33.84 
4| 2.26 | 2.52! 3.60 
Cuckoo. 
cr A, { ore bop iaeea 21.24 25.20 28.16 31.68 | | 
8: 3 6.66 | 9.00 12.60 19.80 22.68 26.28 28.08 30.60. 
Cedarbird. , 
1 12.50 14.00 15.00 19.00/24.00 27.00 29.30 37.00 38.50 
L. wing J 2 11.00 13.00 15,00 17.00 20.50 23.00 24.80 33.00 38.00 | 
in mm. | 3 12.00 13.50 14.00 17.00 20,00 24.00 26.50 33.00 36.50 / | 
4 10.00 12.00 
Cuckoo. 
ss u i) 20 125 are ise. ise." i438 ; 
mmm. ) > 17 
3 Ph 28. 198: 1S 186s. 148” As 

















Cedarbird No. 4 was probably starved by its more vigorous mates, after the 
second day. Cuckoo No, 2 fell out of its nest. “0” indicates the egg. 
cedar waxwing, and has based his results upon a much larger number 
of cases. He also considers that the three stages enumerated correspond 
to stages in the development of muscular coordination, of association 
and the instinct of fear. During the first period, when the power of 
motor coordination is weak, according to this observer, “ the first crude 
discriminations and associations are made,” and the first signs of in- 
stinctive fear noted. In the intermediate period (fourth to seventh 
day), discrimination improves, and association is perfected, while from 
the beginning of the last period “there is an abrupt change in all the 
reactions, the food-reaction ceasing for all the artificial stimuli, except- 
ing occasionally for the visual, and fear begins to develop rapidly 
through several forms of manifestations.” 
Kuhlmann recognizes five different manifestations of fear, begin- 
ning with “ cessation of the food-reaction to stimuli that at first aroused 
it,” and ending with “escape from the nest when approached.” Dis- 
crimination and’ the formation of associations between the food and 
certain stimuli are thought to develop simultaneously, and “ all stimuli 
with which no pleasant associations are already formed are then at the 
same time instinctively feared.” The food-reaction is not only modified 
by association, but is inhibited by fear, and while the development of 
association is gradual, the passage of one manifestation of fear to the 
next in order is often very abrupt. Such animals, he says, “come to 
fear particular things not so much because of unpleasant associations 
that are connected with them, as because the taming process has not 
been completed.” 
