STRUCTURE AND LIFE-HISTORY OF CRITHIDIA MELOPHAGIA. 221 



Pi"'. 4.--Division rosette of pre-flagellates. Two individuals again 

 dividing. Croi^. Delafield's hannatoxylin. 



Figs. 5-8. — Elongating pre-flagellates. Crop. Thionin. 

 Fig. 9. — Large preflagellate, with round nucleus, rod-like blepliaro- 

 plast, flagelluni just differentiating. Crop. Giemsa. 



Fig. 10. — Rounded form. Flagelluni longer than in fig. 9. Crop. 

 Giemsa. 



Fig. 11. — Smaller parasite with large nucleus and long flagelluni. 

 ■Crop. Delafield's heematoxylin. 



Fig. 12.— Parasite, showing elongation of flagellar (anterior) end of 

 the hody. Crop. Giemsa. 



Figs. 13 and 14. — Crithidia with elongated posterior ends. Anterior 

 part of stomach. Giemsa. 



Fig. 15. — Pre-flagellate with posterior blepharoplast. Crop. Giemsa. 



Fig. 16. — Parasite with anterior end more developed. Crop. Giemsa. 



Figs. 17 and 18. — Almost mature flagellates, membranes showing 

 myoneines. Crop. Giesma. 



Figs. 19 and 20.— Practically adult flagellates. Fore-part of stomach. 

 Tiiionin. 



Figs. 21-43. ^Flagellate Stage. 

 Fig. 21. — Small flagellate. Nucleus with chromatin in granules 

 ■extending part way across the body. Rod-like blepharoplast. Intestine. 

 Giemsa. 



Fig. 22. — Flagellate, with well-marked mypnemes on the body. 

 ■Stomach. Gentian violet, x 2250 approximately. 



Fig. 23. — Parasite, with flagelluni almost continuous with the 

 blepharoplast. Nucleus with central chromatin. Stomach. Delafield's 

 hsematoxylin. 



Fig. 24. — Crithidia showing blepharoplast posterior to the nucleus 

 — an uncommon condition. Stomach. Giemsa. 



Figs. 25, 26. — Flagellates showing chromidia in their posterior ends. 

 "Chromatin of nucleus in l;>ars. Stomach. Gienisa. 



Figs. 27-29. — Parasites with somewhat pointed posterior ends. 

 Chromidia present in fig. 29. Intestine. Thionin. 



Figs. 30, 31. — Crithidia showing somewhat alveolar protoplasm. 

 Stomach. Thionin. X 2250 approximately. 



Fig. 32. — Flagellate with blunt posterior end, round nucleus contain- 

 ing large chromatin granules, and extending across complete ))re.idth 

 of body ; blepharoplast curved. Stomach. Thionin. x 2250 approxi- 

 mately. 



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