282 A THEORY OF HEREDITY VIII 



of the originally-formed egg- cells retain their vitality 

 and form-individuality for more than forty years. 

 How, we may ask, during that time are they subjected 

 to the influence of new polar forces acquired by the 

 other units of the body ? We know that they are so 

 impressed, or have such influences propagated to them. 1 

 Is it by " action at a distance," or by the contact action 

 of circulating infective gemmules ? 



Such being the state of speculation, in England at 

 any rate, with regard to the mechanical explanation 

 of heredity, we return to Professor Haeckel's recently 

 enunciated theory of the Perigenesis of plastidules. 



It is clear, to begin with, that Professor Haeckel 

 has either never studied or has forgotten Mr. Herbert 

 Spencer's writings. His attempt to substitute some- 

 thing better for Mr. Darwin's provisional hypothesis 

 of Pangenesis, as he tells us, has its origin, to a great 

 extent, in the admirable popular lecture of Professor 

 Ewald Hering of Prague, " Uber das G-edachtniss als 

 eine allgemeine Function der organisirten Materie" 

 [On Memory as a General Function of Organised 

 Matter], published in 1870, and to some extent, 

 including terminology, is based on an essay by Elsberg, 

 of New York, published in the Proceedings of the 

 American Association, Hartford, 1874. With the latter 

 of these publications I am only acquainted through 

 Professor Haeckel's citations, but with the former at 

 first hand. Professor Hering gives a brief outline, in 

 the lecture in question, of the fundamental doctrine 

 of physiological psychology, which had been previously 



1 See note on page 286. 



