360 THE CELL 



the individual in question are represented ; therefore, the nucleus 

 is the organ of heredity ; the remaining protoplasm of the cell 

 contains practically only those idioblasts which have become 

 active in it and which can multiply rapidly in an adequate man- 

 ner. We have, therefore, to distinguish between two modes of 

 multiplication of the idioblasts ; the one referring to all of them, 

 which results in nuclear division and in their equal distribution 

 amongst the two daughter cells ; and the other, which to a certain 

 extent, is a multiplication connected with function ; and this latter 

 only affects those idioblasts which have become active ; moreover, 

 it is connected with the material changes which occur in them 

 and it takes place chiefly in the protoplasm, outside the nucleus. 



This conception is another indication that the protoplasm is 

 composed of small elementary units of substance, as has been 

 assumed latterly by several investigators, who have started various 

 theories; as for instance Altmann (II. 1), in his theory of bio- 

 blasts, and Wiesner (IX. 35), in his recent work "Die Elementar- 

 structur uvd das Wachsthum der lebenden Substanz." The proto- 

 plasm, like the nucleus, consists of a large number of small 

 particles of material, which differ as to their chemical composition, 

 and which have the power of assimilating material, of growing 

 and of multiplying by division. (Omne granulum e granulo, as 

 Altmann expresses it.) Material for growth is supplied by the 

 fluid, which bathes the nucleus and protoplasm, and in which 

 plastic materials of the most different kinds (albumen, fats, carbo- 

 hydrates, salts) are dissolved. 



In order to distinguish the idioblasts of the nucleus from those 

 of the protoplasm, we will call the latter " plasomes," a name 

 which has been used by Wiesner. 



As the plasomes (or as it were the active idioblasts) are, accord- 

 ing to the theory of " intracellular pangenesis," supposed to be 

 derived from the idioblasts of the nucleus, so they may also form 

 the starting-point of the organic products of the plasma, since 

 according to their specific characters, they join to themselves 

 various substances ; for instance, certain kinds of plasomes, by 

 combining with carbo-hydrates, might produce the cellulose mem- 

 brane, or by combining with starch the starch granules ; hence 

 they might be designated, the cell-membrane formers or starch 

 formers. 



Thus the most different occurrences in cell life may be regarded, 

 from a common point of view, as vital processes taking place in 



