Edinger, Comparative Psychology. 451 



from the enlargement of the palaeencephalon whose various parts 

 here reach a perfection which they attain nowhere else. We know 

 that in birds nearly all parts of this palaeencephalon are connected 

 with the cortex; that particularly the brain-part connected with the 

 oral sense (the lobus parolfactorius) is of enormous size; and 

 finally, that from the optic termini an especially large numberof 

 fibers lead to the cortex. 



A priori one would infer from this structure that the instinctive 

 actions must be of much greater variety and perfection, and that 

 also the capacity for forming associations must be much greater 

 than in reptiles. 



As a matter of fact, the investigation of the psychic behavior 

 of birds — I am speaking now of nest-building, migration, and 

 courtship — has met certain difficulties in the numerous strong 

 instincts whose perfection is so great that it has not always been 

 possible to distinguish them from activities which are dependent 

 upon the cortex. Although we possess many works dealing with 

 the behavior of birds, the observers have only very seldom en- 

 deavored to maintain an objective point of view. I regard the 

 works of WuRM and Greppin as among the best. If one leaves 

 out of account instinctive actions, one is struck with the fact that 

 the new (as compared with reptiles) connections of the palaeen- 

 cephalic optic termini with the neencephalic cortex play the all 

 important role in the behavior of the animal. Birds see and 

 recognize; a single visual characteristic of the object often enables 

 them to judge of the whole. Their actions are for so long a time 

 influenced by a thing seen that one must infer that they possess 

 and make use of memory images. Ducks soon recognize the 

 hunter's screen and avoid it after several of their number have 

 been killed. Eimer relates that on the first day he caught thirteen 

 sparrows in a newly constructed sparrow trap, but afterwards no 

 more. Two years later the trap was again set up but not a bird 

 went into it. Game birds learn so well to recognize the hunter 

 that they distinguish him from wood-choppers, wagons, horses 

 and the like, just as do wild mammals. Upon this fact are based 

 many of the tricks of hunting, such as stealing up behind a horse 

 or arranging a trap under a screen upon which is painted a cow. 

 When partridges see the falcon they crouch down anxiously. Thus 

 it is often the practice to arrest a scattered covey by means of a 

 painted paper kite and then to kill the birds (Wurm). Only birds 



