312 



SCIENCE. 



[N. S. Vol. XII. No. 295. 



On the other hand, it contains much informa- 

 tion which is of value to the student and which 

 the beginner might fail to find out for himself. 

 The discussions of individuality, alternation of 

 generations, and sexuality are especially good. 

 The book is well printed and its fifty-three 

 illustrations are well chosen and clear. 



J. S. KiNGSLEY. 



PKOFESSOE MOSSO'S LECTURES AT THE CLARK 

 UNIVERSITY DECENNIAL. 



Two lectures were delivered by Professor 

 Angelo Mosso at Clark University during its 

 Decennial Celebration, in the summer of 1899, 

 which seem to deserve wider publication than 

 they will obtain through the volume issued 

 and distributed by the university in commem- 

 oration of that event. This volume has been 

 already reviewed in Science, without, how- 

 ever, special reference to the contents of these 

 addresses. 



The former of the lectures, of which notes 

 are here presented, is called ' Psychic Proc- 

 esses and Muscular Exercise.' It would be 

 difficult to exaggerate the importance of the 

 ideas presented, although the campaign against 

 present public opinion which a practical reali- 

 zation of some of its consequences would de- 

 mand might well discourage a Pestalozzi. The 

 logical conclusion has, however, been arrived 

 at both by the psychologist and by the medical 

 man, as well as by the physiologist, who is 

 both. 



One of the most important of the rising be-, 

 liefs of American medical men regarding com- 

 mon school education is corroborated in this 

 address by the eminent Italian. In it he 

 sought to show ' ' how intimately related are 

 mental processes and movements. If we de- 

 sired to make a pedagogical application," he 

 says, "we might say that physical education 

 and gymnastics serve not only for the develop- 

 ment of the muscles, but for that of the brain 

 as well." 



Children should begin reading and writing 

 only after they are nine years old, and it is be- 

 coming evident that as much time should be 

 devoted to muscular exercise as to intellectual 

 exercise. No absolute local separation of move- 

 ment and sensibility is demonstrable. Muscular 



fatigue exhibits phenomena identical with intel- 

 lectual fatigue. Internal reflex phenomena 

 seem largely to condition attention which, 

 therefore, is not wholly within the will's control. 

 Nerve cells have only a small power of resistance 

 and show, on the average, every ten seconds a 

 tendency to rest. It is probable that only part of 

 the brain is active at a time — the various parts 

 relieve each other. The structure of all nerve 

 cells seems to be the same — it is only their re- 

 lations which are different. The more mobile 

 any animal's extremities the more intelligent, 

 other things being equal, he is : the most mo- 

 bile parts are those which are the most sensi- 

 tive. 



The other address, called by Professor Mosso 

 ' The Mechanism of the Emotions,' adds not a 

 little to our knowledge of the somatic aspect 

 of emotion, dealing especially with the sensi- 

 tivity of the bladder — one of the most sensitive 

 of the viscera. 



The seat of the emotions of joy and of sorrow 

 seems to Professor Mosso to lie undoubtedly in 

 the so-called sympathetic nervous system. In 

 1881 he noticed (with Dr. Pellacari) the con- 

 traction of the bladder during weak sensations. 

 Besides those of the bladder, he has studied 

 the movements of the stomach and intestines, 

 including the rectum. 



The bladder's movements are both active and 

 passive, but the former are of chiefer interest 

 and alone are considered here. The experi- 

 ments were conducted both on dogs and on 

 women. The instrument employed was his 

 own plethysmograph, a very valuable hydraulic 

 arrangement too well known to need descrip- 

 tion here. This was connected with the blad- 

 der by means of a ' female catheter. ' The 

 human subjects studied were young women 

 in the hospitals, who, of course, volunteered 

 their services. He recorded in the cases of 

 both the women and the dogs the thoracic and 

 abdominal respiration and the movements of 

 the bladder independently. He considers that 

 the bladder exhibits ' the most delicate reflex 

 movements which occur in the organism. ' The 

 bladder contracted not only to very slight emo- 

 tional stimuli, but also to changes in the or- 

 ganism instigated by problems in mental arith- 

 metic. 



