Studies in Spermatogenesis - LightNovelsOnl.com
You're reading novel online at LightNovelsOnl.com. Please use the follow button to get notifications about your favorite novels and its latest chapters so you can come back anytime and won't miss anything.
PLATE X.
_Odontota dorsalis._
FIGS. 69-70. First spermatocyte, metaphase.
71. First spermatocyte, equatorial plate.
72. First spermatocyte, metaphase, showing metakinesis of the heterochromosomes.
73-74. First spermatocyte, anaphase.
75-76. Second spermatocyte, equatorial plates.
77. Second spermatocyte, showing metakinesis of the small chromosome (_s_).
78. Second spermatocyte, prophase, showing chromosomes longitudinally split.
79-80. Young spermatids, _n_ the chromatin nucleolus.
81-87. A series of stages in the development of the sperm head, showing the various phases in the history of the chromatin nucleolus (_n_).
88. Cross-sections of nearly mature sperm heads.
89-90. Equatorial plates of spermatogonia of abnormal individual, 15 large chromosomes, 2 small ones.
91. First spermatocyte from same testis, spireme stage, showing 2 small chromosomes a.s.sociated with 1 large one and a plasmosome.
92. First spermatocyte from the same testis, metaphase showing a similar heterochromosome group.
93. Second spermatocyte from same testis, equatorial plate, showing 2 small chromosomes.
_Epilachna borealis_ (_Family Coccinellidae_).
94. Equatorial plate of spermatogonium, 17 large chromosomes and 1 small one.
95. First spermatocyte, spireme stage, showing the unequal pair.
96-97. First spermatocyte, late prophases.
98. First spermatocyte, metaphase, showing chromosomes of different forms.
99-100. First spermatocyte, equatorial plate.
101. Unequal heterochromosome pair from a metaphase.
102. First spermatocyte, anaphase; ordinary chromosomes stippled to show more clearly the metakinesis of the unequal pair.
103. Second spermatocyte, equatorial plates.
104. Second spermatocyte, prophase.
105-106. Abnormal giant spermatids, probably in process of degeneration.
_Euphoria inda_ (_Family Scarabaeidae_).
107. Equatorial plate of spermatogonium, 20 chromosomes. The 2 smallest are the unequal pair of heterochromosomes (_l_ and _s_).
108. Resting spermatogonium, showing plasmosome (_p_).
109. First spermatocyte, spireme stage.
[Ill.u.s.tration: STEVENS PLATE X.
N. M. S. del.
COLEOPTERA]
PLATE XI.
_Euphoria inda._
FIGS. 110-111. First spermatocyte, prophases.
112-113. First spermatocyte, late prophase.
114-116. First spermatocyte, metaphase.
117. First spermatocyte, equatorial plate, _x_ the unequal pair.
118-120. First spermatocyte, anaphase.
121. First spermatocyte, daughter plates.
122. Second spermatocyte, prophase.
123. Second spermatocyte, equatorial plates.
124-125. Second spermatocyte, daughter plates of the two cla.s.ses.
126-127. Second spermatocyte, anaphase.
128-130. Spermatids, _n_ the chromatin nucleolus.
