162 HEREDITY AND ENVIRONMENT 



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- 

 tations is possible. It seems probable, as 

 Boveri has shown, that different chromosomes 

 of the fertilized egg differ in hereditary po- 

 tencies, and where the number of chromosomes 

 is fairly large the number of possible combi- 

 nations of these chromosomes in the germ cells 

 becomes very great. In woman, where there 

 are probably 48 chromosomes,* and, after 

 synapsis, 24 pairs of maternal and paternal 

 ones, the possible number of permutations 

 in the distribution of these chromosomes to 

 the different egg cells would be 2 24 , or 

 16,777,036, and the possible number of differ- 



* See footnote p. 153. 



