TUE Sl'KR-MATÜJENESiS OF DOMESTIC MAMMALS. 251 



I'liAl'E VI. 

 All figures nre from mouse. 



Figs. 3'J-ll. I'olnr views of metnphnse of first divi.sion. 



Fig. 12. Polar view of metftphnse of first division, showing mitochond rial grnnules. 



Figs. 13-13. Siile views of metaphiise of first division, showing cUromatoid body and 

 remnant of nucleolus. 



Figs. 46-51. Side Wews of early anaphase of first division, showing XY-chromosomes. 



Fig. 52. Division of sex-chromosome in first division. 



Figs. 53-58. Chromosomes of late nn^iphnses of first division. 



VUXVI-: VII. 



All figures are from mouse. 



Figs. 59-fil. Polar \iews of metaphnses of second reduction division. 



Fig. 62. Side view of metaphase of second reduction division. 



Figs. C3-6'l. Side views of anaphases of second reduction division, showing mitochondrial 



granules and chromatoid body. 

 Fig. 65. Chromosomes of anaphase of second reduction division. 

 Fig. 66. Sidj view of telophase of second division. 



Figs. 67. 68. Spermatids, showing idiozome, chromatoid bxly and centrosome. 

 Figs. 69-81. Showing transformation of spermatids into spermatozoa. 



rrAii: vin. 



Figs. 82-84 are from mouse. Figs. 85-102, from rabbit. 



Figs. 82-S3. Development of spermatozoa, showing fat-granules. 



Fig. 81. Rii^e spermatozoon. 



Figs, 85, 86. Spermatogonia in prophage, showing long chromatin spiremes. 



Figs. 87-91. Polar views of metaphases of spermatogonia, showing variation in number of 

 chromosomes. 



Fig. 1)2. Side view of metaphase of spermatogininm. 



Fig. 93. Side view of metaphase of spermatogonia! division, showing mitochondrial granules 



Fig. 91, Side view of anaphase of spermatogonium, showing rod-shaped chromosomes. 



Fig, 95. Telophase of spermatogonia! division. 



Pig. 96. Spermatocyte in leptoteue stage. 



Fig. 97. Synaptic stage. 



Fig. 93. Synaptic stage, showing mitochondrial granules. 



Fig. 99. Post-synaptic stage, showing mitochondrial granules and parallel arrangement of 

 chromatin spiremes. 



Fig. 100. Post-synaptic stage. 



Figä. 101, 102. Spermatocytes in diplotene stage. 



