440 J' A- MURRAY, The Nebenkern in the spermatogenesis of Pulmonata. 



Plate 33. 



Fig. 13. Slightly later prophase. Same fixation, X 2250. 



Fig. 14. Still later prophase — distortion of nuclear membrane. 

 Large mass of sphere fragments near one centrosome. Hermann's 

 mixture pyroligneous acid. Alcoholic haematoxylin and potassum bichro- 

 mate. X 2250. 



Fig. 15. Amphiaster. Sphere fragments around both poles. Her- 

 mann's mixture pyroligneous acid, alcoholic haematoxylin with per- 

 manganate of potash differential on slide saffranin. X 2250. 



Figs. 16 — 20. Spermatocytes of second order. Hermann's mix- 

 ture and pyroligneous acid, haematoxylin on slide, saffranin. 



Fig. 16. Telophase of first ripening division, Verbindungsfasern 

 becoming transformed into Zellkoppel. X 2250. 



Fig. 17. Later stage, nucleus vesicular, coarse chromatin network, 

 fusion of Verbindungsfasern with old Zellkoppel. X 2250. 



Fig, 18. Chromosomes differentiated for second division, sphere 

 still single. X 2250. 



Fig. 19. Late prophase, chromosomes apparently longitudinally split- 

 ting. X 2250. 



Fig, 20, Amphiaster second ripening division, vide text. X 2250. 



Figs. 21—25. Arion, spermatocyte L 



Fig. 21. Resting spermatocyte, vide text. X 2250. 



Fig. 22. Prophase. Large sphere fragment with one pole. X 2250. 



Fig. 23. Amphiaster. X 2250. 



Fig. 24, Metaphase. X 2250, 



Fig. 25. Telophase. X 2250. 



