INTRA-UTERINE INFLUENCES. 295 



" According to Hausmann, the effect of variations 

 of the external atmosphere is visible in the unusual 

 number of blind colts and hydrocephalic pigs which 

 are born after a wet summer." * 



Atrophy, and even amputation of the limbs of the 

 foetus, has in many instances been produced by the 

 mechanical pressure of ligamentous bands, or loops of 

 the umbilical cord. 3 



From the facts already presented, it must be seen 

 that malformations of the embryo are produced by 

 well-known physiological and pathological conditions, 

 that interfere with the normal process of develop- 

 ment. 



From what is now known of the laws of embryo- 

 logical development and the causes of abnormal varia- 

 tions, the theory that the imagination of the mother 

 has a direct influence in producing malformations, or 

 impressing peculiar marks upon the embryo, appears 

 to be based on insufficient evidence. 



1 Allen Thomson, " Cyclopaedia of Anatomy and Physiology," article 

 " Generation," vol. ii., p. 475. 



8 Montgomery, loc. cit., pp. 327-330. 



