TRANSMISSIBLITY OF FUNCTIONAL MODIFICATIONS 109 



function of organized matter'], 1870. As this essay probably con- 

 tains the best that can be said in favour of a transmission of functional 

 modifications, and as it also includes some indisputable truths, we may 

 consider it in some detail. 



Hering is undoubtedly right in regarding 'the phenomena of 

 consciousness as functions of the material changes of organic sub- 

 stance, and conversely.' That is, he believes that every sensation, 

 every perception, every act of will arises from material changes in 

 the relevant nerve-substances. But we know that 'whole groups 

 of impressions, which our brain has received through the sense- 

 organs, are stored up in it, as if resting, and below the margin of 

 consciousness, to be reproduced when occasion arises, in correct order 

 of space and time, and with such vividness, that we may be deceived 

 into regarding as a present reality what has long ceased to be present.' 

 There must therefore remain in the nerve-substance a 'material 

 impact,' a modification of the molecular or atomic structure, which 

 enables it ' to ring out to-day the note that it gave forth yesterday 

 if only it be rightly struck.' 



Hering attributes a similar power of memory and reproduction 

 to the germ-substance ; he believes that he is justified in making 

 the assumption that acquired characters can be inherited, although 

 he admits that it 'appears to him puzzling in the highest degree' 

 how characters which developed in the most diverse organs of the 

 mother-being can exert any influence on the germ. That he may 

 be able to assume this he points to the interconnexion of all organs 

 by means of the nervous system ; it is this that makes it possible 

 that 'the fate of one reverberates in the other, and that, when 

 excitement takes place at any point, some echo of it, however dull, 

 penetrates to the remotest parts.' To the delicate-winged com- 

 munication by means of the nervous system, which unites all parts 

 among themselves, must be added the general communication by 

 means of the circulation of the fluids of the body. According to 

 Hering's view, the germ experiences, in some degree, in itself all that 

 befalls the rest of the organs and parts of the organism, and these 

 experiences stamp themselves more or less upon its substance, just as 

 sense-impressions or perceptions stamp themselves upon the nerve- 

 substance of the brain, and these experiences are reproduced during 

 the development of the germ, just as the brain brings memory-pictures 

 back to consciousness. He says, ' If something in the mother-organism 

 has so changed its nature, through long habit or exercise repeated 

 a thousand times, that the germ-cell resting in it is also penetrated 

 by it in however weakened a fashion, when the latter begins a new 



