STRUCTURE AND LIFK-HISTORY OF CRITHIDIA MELOPHAGI A. 223 



daughter-forms. The flagella have interlocked. Intestine. Delafield's 

 hseniatoxylin. The parasites represented in fig. 51 divided sub-equally. 



Fig. 53. — Sub-equal division. Daughter - organisms are almost 

 separated. Intestine. Delafield's hseniatoxylin. 



Figs. 54, 55.— Parasites about to separate. Stomach. Giemsa. 



Fig. 56. — True division-rosette. The separation of the daughter- 

 individuals takes place from the flagellar end backwards, so that in 

 a rosette the posterior ends of the organisms are centrally directed. 

 Stomach. Thionin. 



PLATE 13. 



Figs. 57-94. — Stages of the Parasite in the Ovary, Eggs, 



and Puparia. 

 (The eggs in figs. 58, 64, 65 are represented dia grammatically.) 



Fig. 57. — The flagellate as it penetrates the ovary. Delafield's 

 hseniatoxylin. 



Fig. 58. — Flagellate in the act of penetrating a young egg, the blunt 

 end of the parasite being used. Thionin. The egg of Melophagus 

 o villus is represented diagrainmatically. 



Figs. 59, 60. — Flagellates from ovary. Flagella somewhat reduced. 

 Giemsa. 



Figs. 61-63. — Flagellates from within the egg. Giemsa. 



Figs. 64, 65. — Rounding-up forms of C. meloplagia within eggs. 

 Delafield's hseniatoxylin and fresh preparations. Eggs of M e 1 o p h a g u s 

 represented diagramniatically. 



Figs. 66-72. — Series of parasites showing successive stages in shorten- 

 ing and rounding-up of flagellates when within the eggs. Delafield's 

 hseniatoxylin. 



Figs. 73, 74. — Parasites showing nuclear division. Very young 

 puparium. Giemsa. 



Figs. 75-77. — "Plasmodial " stages of C. melophagia in developing 

 puparia. Peripheral blepharoplasts seen. Giemsa and fresh prepara- 

 tions. 



Figs. 78-81. — Rounded parasites resulting from plasmodial forms. 

 Delafield's hsematoxylin. 



Figs. 82-84. — Parasites produced by growth of forms similar to those 

 shown in fig. 81. Giemsa. 



Figs. 85-87. — Rosettes of somewhat oval parasites from young 

 puparium. Delafield's hseniatoxylin. 



Fig. 88. — Well-defined division-rosette from mature puparium. 

 Giemsa. 



