EXPLANATION PLATES XVI, XVII, XVIII & XlX-continued. 



PLATE XVIII. 



Fig. 11.— Longitudinal section of the ovary-wall, the germogen, and an 

 egg-string near its smaller end. Chromic acid, (x 165.) 



Pig. 12. — A longitudinal section of an egg-string near its broad end. 

 In one of the follicles an ova is established. Picro- sulphuric acid. 

 (X 450.) 



Fig. 13. — The same as Fig. 12, shoveing different stages of the ovum. 

 (X 450.) 



Fig. 14. — A longitudinal section near the middle of an egg-string. The 

 larger ovum is nearly mature. Picro-sulphuric acid. (X 450.) 



PLATE XIX. 



All preparations, except Fig. 19, were treated with acetic acid and 

 clarified with a mixture of glycerine and potassic acetate. 



Fig. 15. — An egg found Hoating in the ovarian fluid, (x 450.) 



Fig. 16. — Just after deposited, showing the "spiral asters." (X 450.) 



Fig. 17. — Optical section through the lower aster of Fig. 16, seen from 

 above, (x 450.) 



Fig. 18.— Five minutes after laid, (x 450.) 



Fig. 19. — About the same stage as Fig. 18. Fresh condition. ( x 450.) 



Fig. 20. — Three hours and a half after laid. ( x 450.) 



