ON THE CAUSES OF VARIATION. 813 



motlier on lier offspring, and belief in it is still very prevalent 

 among women themselves, of all classes. Women alone are able 

 to speak or feel in this matter from experience, and the almost 

 universal belief in the influence, among those who have any ex- 

 perience at all, should make us hesitate to discard it too summa- 

 rily. From facts within my own personal knowledge I have long 

 believed in this influence, and the more I have been able to collect 

 reliable data bearing upon it, the more confirmed have I become 

 in the conclusion that the emotional experiences of the mother 

 affect the issue in varying degree, according to the intensity of 

 the emotion. When sudden and excessive, as in rage, fright, 

 repugnance, etc., or where prolonged or accumulative, as in con- 

 tinued brooding,, it may induce nervous disorders, and even mental 

 aberration, idiocy, or insanity ; or, again, physiological change, as 

 atrophy or increase of parts, and other peculiarities which have 

 relation to the form or character of the inducing mental mani- 

 festation or shock in the parent. Investigation of this, as of all 

 subtle phenomena, is attended with the difficulty of separating 

 the chaff of fancy from the grain of reality. The method pur- 

 sued by Darwin is unsatisfactory, as it dealt with normal condi- 

 tions which furnish no evidence and with the fanciful or notional 

 side of the subject. The literature of the subject is extensive and 

 quite interesting, and I would refer particularly to the work and 

 writings of Viellard, Schonfeld, Demangeon, Lucas, F^r^, and 

 Brown-S^quard. Two other difficulties confront the investigator : 

 first, the somewhat unsatisfactory state of neurology and the diffi- 

 culty of experimental research therein, as indicated by Vice-Presi- 

 dent Bowditch before this section two years ago ; secondly, the 

 aversion, from feelings of delicacy, on the part of the persons con- 

 cerned, to publicity of the more marked and striking evidence. 

 The phenomena of hypnotism, proving as they do that physiologi- 

 cal results may be induced through the imagination of the subject 

 acted on by the mind of the hypnotizer, are suggestive in this 

 connection, the work of Charcot in Paris more particularly show- 

 ing how powerful the action may be, and how the effects of actual 

 medicines may be produced by the use of imagined ones. The 

 mind of the hypnotized under these conditions is brought into 

 those exceptional and exalted conditions which are necessary in 

 the case of the mother to produce on her offspring the effect 

 which we are discussing. The recent experiments of Mr. C. T. 

 Hodge on the effects of stimulation on the nucleus and cell-body 

 and on protoplasm are also interesting here, showing, as they do, 

 decrease in the two former and vacuolation of the latter as the 

 result. 



The history of science is present to tell us that common and 

 persistent belief, based on experience, has not infrequently been 



