Author's Introduction 7 



phological details of those processes; our knowledge is 

 yet too limited for that. But, following the method of 

 Darwin, to find in the special cases the material substra- 

 tum of the physiological processes, that is our problem. 



As the most important result of cell-investigation of 

 the preceding decades, I consider the theory that all the 

 hereditary predispositions (Anlagen) of the organism 

 must be represented in the nucleus of the cell. I shall try 

 to show that this theory leads us to assume a transporta- 

 tion of material particles which are bearers of the indi- 

 vidual hereditary characters. This does not mean, how- 

 ever, a transportation through the whole organism, nor 

 even from one cell to another, but one restricted to the 

 limits of the individual cells. From the nucleus the ma- 

 terial bearers of the hereditary characters are transported 

 to the other organs of the protoplast. In the nucleus they 

 are generally inactive, in the other organs of the protoplast 

 they may become active. In the nucleus all characters 

 are represented, in the protoplast of every cell only a 

 limited number. 



The hypothesis, therefore, becomes one of intracellu- 

 lar pangenesis. To the smallest particles, of which each 

 represents one hereditary characteristic, I shall give a 

 new name and call them pangens, because with the desig- 

 nation "gemmule" (Keimchen) is associated the idea of a 

 transportation through the whole organism. 



