312 SECRETS OF ANIMAL LIFE 



esting is that the changes thus induced "by idea- 

 complexes, formed and maintained without any 

 emotion " are small compared with those brought 

 about by conditions predominantly emotional. 



Dr. Dearborn has worked at the factors altering 

 blood pressure, and he makes the notable statement 

 that in the " general stimulation of the essential 

 circulation in all constructive parts of the body, 

 such as the brain, the muscles, and the digestive 

 organs, joy exerts one of its most conspicuous 

 benefits, and one that no one can doubt or ignore." 

 It is interesting to ask, though we may never be 

 able to answer, whether the apparent joyousness 

 of many birds, expressed especially in song, but 

 also in dance and exuberant flight, is correlated 

 with their singularly perfect digestive capacity, 

 their fine circulation and muscularity. If birds 

 have no genuine joie de v'wre, they make at times 

 an extraordinarily good imitation of it, and we 

 should like to know whether they are eupeptic 

 because they are joyous, or joyous because they 

 are eupeptic. For sometimes an organism is a 

 mind-body and at other times a body-mind. 



For man, however, there is no doubt that affective 

 states of joy and grief cause rapid changes in blood 

 pressure. " In one case," Dearborn tells us, " an 

 imaginary kiss caused in ninety seconds a rise of 

 at least twenty millimeters of mercurial pressure; 

 while in another individual a suddenly recalled 

 grief raised it in less time thirty per cent, more than 

 that." A large variation in blood-pressure in 



