KOO Journal of Comparative Neurology and Psychology. 



tive, and certain other stimuli, of low intensity and of themselves 

 incapable of influencin;^ the brcathini;. ' 



2. Olfactory. Oil of bergamot and lily of the valley pro- 

 duced no appreciable reactions. A slight sensitiveness was 

 shown to asafoetida (see Fig. 4). The response was very simi- 

 lar to that caused by the sound of the bell, though much less 

 pronounced. Turpentine and ammonia produced marked reac- 

 tion, which consisted in quickening and deepening, with great 

 irregularity. In some cases the expiration was clearly active 

 and greatly emphasized. Considering how poorly the sense of 

 smell is developed in birds," it may be doubted that these reac- 

 tions were of a purely olfactory character, although the mucous 

 membranes may have been irritated by the chemicals used. 



/•"4^ ./. Reaction to odor of asatbetida. 



J. Mechanical. The breathing was extremely sensitive 

 to jars of all kinds, whether from the table on which the sup- 

 port rested, or from other parts of the room. Disturbances 

 were caused even by slight vibrations proceeding from remote 

 parts of the building. A slight jar would produce a temporary 

 quickening and shallowing. A violent jar (see Fig. 5) or a jar 

 accompanied by another stimulus, would at first quicken the 

 movement, but later almost completely suspend it, a condition 

 from which the animal would sometimes quickly recover, though 

 often the interruption was more serious. It is a significant fact 



'Delabarre, E. B. I/intluence de raltention sur les moiivements respira- 

 toires, Revue Philosophujiie, 33, 639-649. 1892, 



'Hill, A. Can Birds Smell? A^atitrc, 71, 318-319. 1905. 



Xavier, R. Le sens de I'odorat chez les oiseaux, Revue scientifique, 12, 

 144-148. 1897. 



