1914] 



SHARP— SPERMATOGENESIS IN MA RSI LI A 



431 



Fig. 23. — Third spermatogenous mitosis: prophase. 

 Fig. 24. — Late prophase: centrosomes disorganizing in cytoplasm. 

 Fig. 25. — Anaphase: old centrosomes disorganizing; newly formed cen- 

 trosomes at poles. 



Fig. 26. — "Tassement polaire" stage: old centrosomes have undergone 

 division; new centrosomes greatly enlarged. 



Fig. 27. — Telophase: centrosomes beginning to divide. 



Fig. 28. — Telophase: division of upper centrosome nearly completed; 

 lower one undivided. 



Fig. 29. — Cell of eight-celled stage: centrosomes (blepharoplasts) moving 

 apart. 



Fig. 30. — The same, more advanced. 



Fig. 31. — Fourth spermatogenous mitosis: prophase; spindle forming from 

 radiations; blepharoplast becoming vacuolate. 



Fig. 32.— Late prophase: blepharoplast more irregular. 



F IG - 33- — Late anaphase. 



Fig. 34. — Telophase: blepharoplast breaking up. 



Figs. 35, 36. — Spermatids: blepharoplast has fragmented further and is 

 beginning to form band. 



Fig. 37. — Early stage of metamorphosis of spermatid: blepharoplast 

 shows double structure in certain parts. 



Fig. 38. — Later stage: blepharoplast grows out freely beyond one end of 

 nucleus. 



Fig. 39. — Cross : section of cell in same stage: sections of nucleus with 

 closely appressed blepharoplast at right and left; starch and other disorganized 

 material in cytoplasm. 



Fig. 40. — More advanced stage: cilia growing out from blepharoplast. 



Fig. 41. — Spermatozoid shortly after escape from microspore: cilia only on 



middle coils; length 15.3 /x. 



Fig. 42. — Spermatozoid in gelatinous material about megaspore, fixed 



over osmic fumes; length 50 /x. 



