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83 
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Description of Illustrations, 
Plate I. 
(All illustrations made at a magnification of 1500 diameters.) 
Fig. 1. Metaphase plate of chromosomes of primary spermatogonium ; 17 chro- 
mosomes (diploid group = 16 autosomes and 1 monosome). 
Fig. 2. Secondary spermatogonium with restirg nucleus. 
Fig. 3. Prophase stage showing segmenting monospireme and centrosphere 
(idiozome). 
Fig. 4. Late prophase; spindle seen in side view; largest chromosome probably 
the accessory. 
Figs. 5 and 6. Metaphase plates of secondary spermatogonia (premeiotic cells — 
Moore and Walker) showing 17 chromosomes. 
Fig. 7. Metaphase plate of dividing interstitial cell with 17 chromosomes. 
Figs. 8, 9 and 10. Resting primary spermatocytes (meiotic cells; protobroch 
nucleus — Winiwarter). 8 shows three plasmosomes; 9 and 10, each a chromatin- 
nucleolus. 
Figs. 11 and 12. Presynaptic stages (leptotene stage • — Winiwarter) showing 
a thickening continuous (?) monospireme. 
Fig. 13. “Bouquet stage” (contraction pliase), height of loops about half the 
diameter of nucleus; two loops have opened up, their free ends in close apposition; 
loops converge on point where centrosphere (idiozome; this one shows a centrosome) 
is located; this point also the place where the accessory chromosome is invariably 
situated. 
6 * 
