176 M. LOUISE NICHOLS. 



EXPLANATION OF PLATE II. 



FIG. 22. The heterochromosome x. 



FIG. 23. Side view of the first maturation division. Metaphase. 



FIG. 24. Anaphase. Late division of the microchromosomes. 



FIG. 25. Telophase. Traces of the late division of the microchromosomes. 



FIGS. 26-33. Spermatids. 



