THE OVARIAN EGG OF LIMULUS. 213 



Fig. 34. Young Limulus, six-inch ; transverse section of ovarian tube showing 

 oogonia ; the spireme of karyokinesis, and a growing oocyte. The young germi- 

 nal vesicle contains a nucleolus ; in the cytoplasm, close to the germinal vesicle, 

 the crescent-shaped archoplasm. Method : nitro-picro-sulph., lithium-carmine, 

 Lyon's blue. Archoplasm alone a deep blue. 



Fig. 35. .Six-inch animal ; longitudinal section ovarian tube ; chromatin thread 

 — spireme of karyokinesis. Method : Merkel's fluid, Heidenhain's iron-haema- 

 toxylin, oc. i, obj. 7; t.p., tunica propria ; p.c, peritoneal coat. 



Fig. 36. SLx-inch animal ; transverse section ovarian tube, cut obliquely ; 

 metaphase and anaphase of karyokinesis ; centrosome at the pole of one spindle 



Fig. 37. Seven-inch animal ; transverse section ovarian tube ; oogonia in 

 karyokinesis ; spindles ; equatorial plate. Method : Merkel's fluid, Heidenhain's 

 iron-haematoxylin. 



Fig. 38. Seven-inch animal ; transverse section of ovarian tube ; oogonia ; 

 growing oocyte with blue archoplasm. Method (3) (see method), Lyon's blue, 

 lithium-carmine. 



Fig. 39. Seven-inch animal ; ovarian tube ; oogonia ; growing oocyte forming 

 a diverticulum, and surrounded by the tunica propria and by the nucleated peri- 

 toneal mantle. Blue archoplasm conspicuous. 



Fig. 40. Seven-inch animal ; oblique section of ovarian tube, showing three 

 growing oocytes, one of which has formed a diverticulum, and remains attached 

 only by a narrow stalk ; enclosed first by the tunica propria, and second by the 

 peritoneal nucleated coat. Method : No. 3, Lyon's blue and lithium-carmine. 

 Blue archoplasm very distinct. 



Fig. 41. Thirteen-inch animal; transverse section of ovarian tube, showing 

 the relation of the ovarian tube, lined with an epithelium, which is bounded by 

 the tunica propria, t.p., to the investing mantle or peritoneal coat, p.c. The point 

 of attachment of the tube is seen to be also the point of origin of the eggs. From 

 this point the eggs are seen to increase in size, regularly, to the point opposite 

 where the largest egg is found. 



Figs. 42-47. Growing oocytes from ovary of animal seven inches. All drawn 

 with Leitz camera, yV oil immersion, and showing the centrosome and archoplasm, 

 and the relation of these to the cytoreticulum. Method (3). 



Fig. 42. Eosin and nigrosin. 



Figs. 43, 44. Lithium-carmine and Lyon's blue ; archoplasm and centrosome, 

 blue ; everything else, red. 



Figs. 45, 46. Delafield's haematoxylin and picric acid ; centrosome and sphere, 

 yellow ; everything else, blue ; sphere, very distinct. 



Fig. 47. Weigert's picrocarmine ; archoplasmic sphere ; cytoreticulum and 

 central radial structure very distinct. 



Fig. 48. One of the smallest eggs from an ovarian tube, like that shown in 

 Fig. 41. A distinct centrosome in the center of a light area, in the widest portion 

 of the metaplasmic zone surrounding the germinal vesicle. In the latter, a promi- 

 nent nucleolus. 



Figs. 49-104, log, 114. The entire series of figures from Fig. 49 is drawn on 

 the same scale, Leitz camera, oc. i, obj. 5. 



Fig. 49. One of the smallest eggs observed in the adult animal, showing a 

 germinal vesicle, g.v., with a granular nucleolus ; a very distinct blue sphere, sph., 

 with bright-red central granules. Method : Merkel's fluid, safranin, and Lyon's 

 blue. Sphere, sph., alone bright blue ; everything else, red. 



