DK. W. H. EANSOM ON THE OVUM OE OSSEOUS EISHES. 
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Fig. 2. The buttons, when not deformed by mechanical violence. X 200. 
Fig. 3. Section of yelk-sac near the apex of the micropyle : — a , cut edge ; b, folded edge ; 
c, apex of the micropyle. 
Fig. 4. The micropyle, front view, the apex in focus. X 200 (the fine dotting is too 
coarse). 
Fig. 5. An unimpregnated egg under pressure, the micropyle ( b ) in profile projecting 
into the discus proligerus (a). 
Fig. 6. An egg, five minutes after impregnation, showing the funnel of the micropyle 
(b), and the pit in the discus proligerus (a). 
Fig. 7. Escaped and partially emptied inner sac : — a, food-yelk ; b. formative yelk changed 
by the action of water. 
Fig. 8. An egg crushed forty-five minutes after impregnation : — a, contents escaping at 
the rupture in the yelk-sac ; b, collapsing inner sac thrown into folds ; c, ger- 
minal disk. 
Fig. 9. An escaped germinal vesicle in the fluids of the egg : — a , the germinal spots dis- 
placed ; b, the colloid matrix changed and faintly granular ; c, escaped yellow 
droplets ; d, free oil-globules. X 200. 
Fig. 10. The same vesicle acted on by water: — a , the germinal spots vacuolating, with 
dark hard outlines and irregular forms ; b. the colloid content or matrix of 
the spots, more darkly granular and vacuolating. X 200. 
Fig. 11. A portion of the same vesicle more highly magnified: — a , a germinal spot 
vacuolating. X 400. 
Fig. 12. Youngest ova seen ; no primitive yelk around the germinal vesicles. 
Fig. 13. a, an ovum of the smallest size seen furnished with primitive yelk ; b, an ovum 
of somewhat larger size changed by imbibition of water, so that the germinal 
spots have vanished ; c, escaped germinal vesicle without contents ; d, free 
granular matter from larger eggs ; e, stroma of ovary. 
Fig. 14. An ovum of group 2, showing granularity of the surface of the yelk, oil-drops 
distributed, and germinal spots vanished from prolonged action of water 
through the substance of the egg. 
Fig. 15. An ovum of group 3, escaped from its yelk-sac, exhibiting the subangular form 
indicative of its solidity : — a , clearer zone around the germinal vesicle ; b, gra- 
nular aspect of the superficial part of the primitive yelk after the action of 
water. 
Fig. 16. Germinal vesicle with its colloid matrix sustaining the germinal spots in their 
natural positions. Seen in the fluids of the ovary. (The drawing is faulty in 
showing the spots as if those nearest the observer were central.) 
Fig. 17. A germinal vesicle which has imbibed water unequally, the colloid matrix 
retaining the germinal spots in their natural peripheral position. 
Fig. 18. A free germinal vesicle uninjured mechanically, but acted on by water for 
seven hours, the position of the spots and the vesicular wall not changed. 
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