130 THE CAUSATION OF DISEASE. 



to day and year to year, it would follow, from the Spencerian 

 dictum above quoted, that no two germs or sperms could be 

 exactly alike, for it is utterly impossible for the conditions 

 of birth to be exactly alike in any two cases ; but, inasmuch 

 as the bodily state does vary from day to day and from year 

 to year, we should expect those germs and sperms to be most 

 alike which are produced at or about the same time, for in 

 such cases the conditions of germ and sperm birth are most 

 alike ; and this, as we shall see, is the case.* 



We have next to take into account the influence of the E 

 upon the embryo during the months of gestation. This, 

 though very important, is far less so than the earlier influence 

 just spoken of. It is wrought in a twofold way, and in a two- 

 fold way only — (i) Through the mother's blood ; (2) Through 

 modifications of external pressure. Such being the case, one 

 is induced a priori to doubt the popular notions concerning 

 maternal impressions.! Dr. R. Lee believes that many cases 

 of idiocy are caused by mental distress in the mother whilst 

 with child, and it is noteworthy that from time immemorial 

 men have attributed great influence to the woman's surround- 

 ings while pregnant. Thus, in some countries, curious objects 

 are placed about the chamber, and are supposed, by working 

 on the mother's mind, to influence her offspring. All will 

 certainly agree that the mind of the pregnant woman should 

 be kept in a quiet and composed state, but this is chiefly for 

 her own sake, for the emotional being of the pregnant woman 



* In connection with this subject the reader may recall the opening words of 

 " Tristram Shandy" : — "I wish either my father, or my mother, or, indeed, both 

 of them, as they were in duty both equally bound to it, had minded what they 

 were about when they begot me ; had they duly considered how much depended 

 upon what they were then doing ; that not only the production of a rational being 

 was concerned in it, but that possibly the happy formation and temperament 

 of his body, perhaps his genius and the very cast of his mind ; and, for aught 

 they knew to the contrary, even the fortunes of his whole house might take 

 their turn from the humours and dispositions that were then uppermost. Had 

 they duly weighed and considered all this and proceeded accordingly, I am 

 verily persuaded I should have made quite a different figure on the whole from 

 that in which the reader is likely to see me. Believe me, good folk, this 

 not so inconsiderable a tiling as many of you may think it." — La URENCE 

 Sterne. 



f Tot & resume" of the main facts connected with this subject see Dr. 

 Fordyce Barker, "American Gynaecological Trans.," 1887. 



