42 THE GERM-PLASM 



nature of the micella, for crystals are not ' mixtures,' but chemi- 

 cally pure substances. And apart from this, we should be wrong 

 in inferring from this passage that Nageli considers the vital 

 properties of a micella dependent on the co-operation oi different 

 molecules united into a single group ; for in the passage quoted 

 above he also states that one molecule of albumen is sufificient 

 for the constitution of a micella. 



For this reason alone it will be seen that the conceptions of 

 the biophor and of the micella do not coincide. They differ also 

 as regards the mode of multiplication : the fundamental impor- 

 tance of this will become apparent later on. The biophors, as 

 bearers of vitality, possess the power of growth and of multiplica- 

 tion by fission, just as is the case in all orders of vital units on 

 which direct observations have been made, beginning with the 

 microsomata, which constitute the chromatin of the nucleus, and 

 passing through the chlorophyll granules, nuclei, and cells, up 

 to the simpler plants and animals. Nageli"s micella also mul- 

 tiply, but the multiplication occurs ' by the free interposition of 

 new micella, similar to, or identical with, those already present,' 

 in the same manner as he supposed the addition of new particles 

 to take place in a starch grain, or as crystals separate from the 

 mother liquor. These new micellae would certainly have to be 

 formed by an influence, exerted by those already present, which 

 cannot be further defined. 



The ' pangenes ■" of de Vries correspond almost exactly to my 

 biophors, for they are also accredited with the functions of growth 

 and multiplication by division, and play a similar part in heredity. 

 The biophors, as will be explained in the following pages, only 

 differ from the pangenes in being constituents of higher units of 

 the hereditary .substance. 



The minute vital particles or ' plasomes," recently assumed by 

 Wiesner, resemble both pangenes and biophors as regards their 

 properties. The part they take in heredity is, however, only 

 hinted at, and it is therefore better for me to use the special 

 term biophor than to press tlie plasomes into the service of my 

 theory of heredity. 



The biophors play the same part with respect to heredity as 

 that which de Vries ascribes to his pangenes, i.e., they are the 

 ' bearers of the qualities or ' characters ' of the cells ; ' or more 

 accurately, the bearers of the cell-qualities. As all living matter 

 consists of biophors, the differences in it can only depend on 



