686 
PSYCHOLOGY: W. CRAIG 
Thus the young dove when learning to drink makes drinking movements 
while searching for the water ; and when its instinct to fly has ripened, it 
may make feints of flying, flapping its wings vigorously, and even aiming 
at an objective point, before it has dared to launch into the air. There 
are all gradations between a true reflex and a mere readiness to act, mere 
facilitation. In many cases the bird needs to learn to obtain the ade- 
quate stimulus for a complete consummatory reaction, and thus to 
satisfy its own appetites. 
An aversion resembles an appetite in that it is a state of the organism 
characterized by agitation and persistency with varied effort; it differs 
from an appetite in that it continues so long as a certain stimulus, re- 
ferred to as the disturbing stimulus, is present, but ceases, being replaced 
by a state of relative rest, when that stimulus has ceased to act on the 
sense organs. An aversion is sometimes accompanied by an innately de- 
termined reaction adapted to getting rid of the disturbing stimulus, or 
by two alternative reactions which are tried and interchanged repeatedly 
until the disturbing stimulus is got rid of. An example of aversion is 
the so-called jealousy of the male dove, which is manifested especially 
in the early days of the brood cycle. At this time the male has an 
aversion to seeing his mate in proximity to any other dove. The sight 
of another dove near his mate is an 'original annoyer.'^ If he sees 
another dove near his mate, he may follow either or both of two courses 
of action; namely, (a) attacking the intruder, with real pugnacity ; (b) 
driving his mate, gently, not pugnaciously, away from the intruder. 
The instinctive aversion impels the dove to truly intelligent efforts to 
get rid of the disturbing situation. 
Instinctive activity runs in cycles. The type cycle, as it were a com- 
posite photograph representing all such cycles, would show four phases 
as follows. 
Phase 1. Absence of a certain stimulus. Physiological state of appe- 
tite for that stimulus. Restlessness, varied movements, effort, search. 
Incipient consummatory action. 
Phase 11. Reception of the appeted stimulus. Consummatory re- 
action in response to that stimulus. State of satisfaction. No restless- 
ness nor search. 
Phase III. Surfeit of the said stimulus, which has now become a dis- 
turbing stimulus. State of aversion. Restlessness, trial, effort, di- 
rected toward getting rid of the stimulus. 
Phase IV. Freedom from the said stimulus. Physiological state of 
rest. Inactivity of the tendencies which were active in Phases I, II, 
III. 
