31 6 J. E. WODSEDALEK. 



PLATE V. 



FIG. 41. Resting stage of an oogonial cell showing two large nucleoli which are 

 undoubtedly the sex-chromosomes. 



FIG. 42. Spireme stage of an oogonial cell showing the two large sex-chromo- 

 somes. 



FIG. 43. An oogonial cell showing thirty-six newly formed chromosomes and 

 the two large sex-chromosomes. 



FIGS. 44 AND 45. Late prophase stages of oogonial cells showing thirty-six 

 ordinary chromosomes and the two sex-chromosomes. 



FIGS. 46 AND 47. Metaphase stages of division of the oogonia showing the two 

 sex-chromosomes at the periphery of the plate. 



FIG. 49. Liver cell in late prophase stage taken from a female foetus showing 

 thirty-six ordinary chromosomes and the two sex-hromosomes. 



FIG. 50. Brain cell in metaphase stage of division taken from a female embryo 

 showing thirty-six ordinary chromosomes and the two sex-chromosomes. 



FIG. 51. Brain cell in metaphase stage of division taken from a male embryo 

 showing thirty-six ordinary chromosomes and only one sex-chromosome. 



FIG. 52. Liver cell in late prophase stage taken from a male foetus showing 

 thirty-six ordinary chromosomes and only one sex-chromosome. 



