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Heredity and Environment 



Ascaris (Fig. 49). In this case Boveri has shown that the nuclei 

 and chromosomes of germ cells and of somatic cells are at first 

 alike whereas the cytoplasm in these cells is unlike; later the 

 nuclei and chromosomes of these two kinds of cells become unlike, 



FIG. 47. CLEAVAGE OF THE EGG OF Styela, showing distribution of the 

 yellow protoplasm (stippled) and of the clear and gray protoplasm to 

 the various cells, each of which bears a definite letter and number. 



