THE CELLULAR BASIS 155 



sexually is unique, the first and last of its 

 identical kind, and although some of these in- 

 dividual differences are due to varying en- 

 vironment, others are evidently due to 

 germinal differences, so that we must conclude 

 that every fertilized egg cell differs in some 

 respects from every other one. 



But are there molecules and atoms enough 

 in a tiny germ cell, such as a spermatozoon, 

 to allow for all these differences? Miescher 

 has shown that a molecule of albumin with 40 

 carbon atoms may have as many as one billion 

 stereoisomers, and in protoplasm there are 

 many kinds of albumin and other proteins, 

 some with probably more than 700 carbon 

 atoms. In such a complex substance as proto- 

 plasm the possible variations in molecular con- 

 stitution must be well nigh infinite, and it can 

 not be objected on this ground that it is 

 chemically and physically impossible to have as 

 many varieties of germ cells as there are dif- 

 ferent kinds of individuals in the world. 



Even with regard to morphological elements 

 which may be seen with the microscope it can 

 be shown that an enormous number of permu- 



