DEVELOPMENT OF THE EMBRYO. 723 



vomiting, and upon her heart as almost to arrest its motion and induce fainting, 

 can we believe that it will have no effect on her womb and the fragile being 

 contained within it ? Facts and reason, then, alike demonstrate the reality of 

 the influence: and much practical advantage would result to both parent and 

 child, were the conditions and extent of its operations better understood." 

 Among facts of this class, there is, perhaps, none more striking than that 

 quoted by the same Author from Baron Percy, as having occurred after the 

 siege of Landau in 1793. In addition to a violent cannonading, which kept 

 the women for some time in a constant state of alarm, the arsenal blew up 

 with a terrific explosion, which few could hear with unshaken nerves. Out 

 of 92 children born in that district within a few months afterwards, Baron 

 Percy states that 16 died at the instant of birth ; 33 languished for from 8 to 

 10 months, and then died ; 8 became idiotic, and died before the age of 5 years ; 

 and 2 came into the world with numerous fractures of the bones of the limbs, 

 caused by the cannonading and explosion. Here, then, is a total of 59 chil- 

 dren out of 92, or within a trifle of 2 out of every 3, actually killed through the 

 medium of the Mother's alarm and the natural consequences upon her own 

 organization, an experiment (for such it is to the Physiologist) upon too large 

 a scale for its results to be set down as mere " coincidences." No soundly- 

 judging Physiologist of the present day is likely to fall into the popular error, 

 of supposing that marks upon the Infant are to b.e referred to some transient 

 though strong impression upon the imagination of the Mother; but there ap- 

 pear to be a sufficient number of facts on record, to prove that habitual mental 

 conditions on the part of the Mother may have influence enough, at an early 

 period of gestation, to produce evident bodily deformity, or peculiar tendencies 

 of the mind. But whatever be the nature and degree of the influence thus 

 transmitted, it must be such as can act by modifying the character of the nu- 

 tritive materials supplied by the Mother to the Fretus ; since there is no other 

 channel by which any influence can be propagated. The absurdity of the 

 vulgar notion just alluded to, is sufficiently evident from this fact alone ; as it 

 is impossible to suppose that a sudden fright, speedily forgotten, can exert 

 such a continued influence on the nutrition of the Embryo, as to occasion any 

 personal peculiarity.* The view here stated is one which ought to have great 

 weight, in making manifest the importance of careful management of the health 

 of the Mother, both corporeal and mental, during the period of pregnancy ; 

 since the constitution of the offspring so much depends upon the impressions 

 then made upon its most impressible structure. 



947. It is frequently of great importance, both to the Practitioner and to 

 the Medical Jurist, to be able to determine the age of a Foetus, from the physi- 

 cal characters which it presents ; and the following table has been framed by 

 Devergiet in order to facilitate such determination. It is to be remarked, how- 

 ever, that the absolute Length and Weight of the Embryo are much less safe 

 criteria, than its degree of Development, as indicated by the relative evolution 

 of the several parts, which make their appearance successively. Thus it is 

 very possible for one child, born at the full time, to weigh less than another. 

 born at 8 or even at 7 months ; its length, too, may be no greater ; but the 

 position of the middle point of the body will usually afford sufficient ground 



* For some valuable observations on this subject, see Montgomery on the Signs of Preg- 

 nancy. Numerous cases have been recorded, during the last few years (especially in the 

 Lancet and Provincial Medical Journal) in which malformations in the Infant appeared 

 distinctly traceable to strong impressions made on the mind of the Mother, some months 

 previously to parturition ; these impressions having been persistent during the remaining 

 period of pregnancy, and giving rise to a full expectation on the part of the Mother, that the 

 child would be affected in the particular manner which actually occurred. 



f Medecine Legale, vol. i. p. 495. 



