i8o A REMARKABLE ANTICIPATION OF 



licreditary' : first instancini:j- the well-known 'porcupine 

 fiimil}-, in which a remarkable i>eculiarity of the [human] 

 skin was transmitted through three successiv^e genera- 

 tions,' and the facts which prove the hereditary nature 

 of complexion, as shown in Section ii. Supernumerary 

 and abnormall)- thickened digits are then brought forward 

 and proved by many examples to be markedly hereditary ; 

 as also 'a singular thickness of the upper lip, in the 

 Imperial house of Austria', introduced it is believed 

 ' many centuries ago, ... by an intermarriage with the 

 ancient house of Jagellon '. 



The last examples of such connate characters are 

 especially significant. * The same observation equally 

 applies to those minute varieties of organization, which 

 give rise to peculiarities of habit or temperament, and 

 j)redispose to a variety of morbid affections, as deafness, 

 scrofulous complaints, and the whole catalogue of dis- 

 orders in the nervous system. Even those singular 

 peculiarities termed idiosyncrasies are often hereditary, 

 as in the instance of a remarkable susceptibility of the 

 action of particular medicines, such as mercury.' 



With regard to the second proposition ' that acquired 

 peculiarities, or characters impressed by adventitious 

 circumstances, and not arising in the spontaneous deve- 

 lopement of the bodily structure, are never transmitted . . .' 

 he remarks, as it has often been insisted upon since, 

 that the conclusion ' is more difficult to establish than 

 the foregoing . . ., since the proofs must needs be of 

 a negative kind. Hut,' he continues, ' there is no want 

 of evidence of this description.' And he again insists, 

 as if he could not put it too clearly and empliatically : 

 ' It seems to be the law of the animal economy, that 

 the organization of the offspring, which as we have seen 

 follows the type given by the natural and original struc- 

 ture of the parent, is unaffected by any change the latter 

 may have undergone, and uninfluenced by any new state 

 it may have accpiired.' 



He then discusses the examples which are supposed 

 to support the opposite conclusion, first mentioning the 

 statement ' that dogs and cats, the tails of which had 



