304 NATHAN FASTEN. 



EXPLANATION OF PLATE 3. 



FIG. 26. Metaphase, primary spermatocyte showing chromatoid bodies along 

 the spindle fibers at opposite poles. 



FIGS. 27 and 28. Polar views, primary spermatocytes, showing 60 chromo- 

 somes. 



FIGS. 29 to 32. Anaphase and telophase stages of primary spermatocytes show- 

 ing the chromatoid bodies at opposite poles. In Fig. 32 the chromatoid bodies 

 are observed to remain in the cytoplasm. 



FIG. 33. Metaphase, secondary spermatocyte, showing a single chromatoid 

 body at one pole. 



FIGS. 34 and 35. Polar views, secondary spermatocytes, showing 60 chromo- 

 somes. 



FIGS. 36 and 37. Anaphase stages, secondary spermatocytes, showing different 

 positions which the chromatoid body may occupy in the dividing cell. 



FIGS. 38 and 39. Telophase stages, secondary spermatocytes. The single 

 chromatoid body is at one pole. 



FIG. 40. The two types of spermatids formed, one without the chromatoid 

 body, and the other containing it. The centrosomes are the minute dark granules 

 found in the cytoplasm of both these types of spermatids. 



FIG. 41. Early stages in the transforming spermatid which contains the chro- 

 matoid body. 



FIG. 42. Stage in which the chromatoid body is expelled from the spermatid 

 that contained it. 



FIGS. 43 to 47. Early transformation stages of spermatids which are minus the 

 chromatid body. Note the reduction of the chromatin and the appearance of the 

 mitochrondria-like mass (m) in the cytoplasm. In Fig. 47 the single karyosome- 

 like body occupying the center of the nucleus may be seen. 



