366 
Crithidia gerridis 
Fig. 53. Two almost separated daughter Crithidia. Stomach. Thionin. 
Fig. 54. Very long form dividing. The organism has divided at the anterior end while 
the posterior end of the body is twisted. Intestine. Delafield. 
Fig. 55. Almost completed equal longitudinal division. Daughter parasites forming a Y. 
Rectum. Giemsa. 
Fig. 56. Marked sub-equal division. The lower daughter organism is much broader than 
the upper one. Stomach. Gentian violet. 
Fig. 57. Daughter organisms about to finally separate, placed at an angle of 180° with 
one another. Stomach. Thionin. 
Fig. 58. Division of very narrow form giving rise to almost Spirochaetiform Crithidia. 
Rectum. Thionin. 
Fig. 59. Very narrow, almost Spirochaetiform Crithidia. Rectum. Thionin. 
Fig. 60. Spirochaetiform Crithidia showing “peg-top” like arrangement. Rectum. 
Thionin. 
Figs. 61—69. Post-flagellate stages, from rectum and faeces. 
Fig. 61. Commencement of encystment. Posterior end withdrawn. Gentian violet. 
Fig. 62. Parasite rounding up. Anterior end less distinct. Giemsa. 
Fig. 63. Anterior end almost withdrawn. Flagellum disappearing. Giemsa. 
Fig. 64. Pear-shaped organism. Flagellum almost gone. Giemsa. 
Fig. 65. Small, rounded form flagellum forming a tag. Thionin. 
Fig. 66. Larger form than in Fig. 65. Very distinct blepharoplast. Gentian Violet. 
Fig. 67. Flagellate almost encysted. Delafield. 
Fig. 68. Cyst with round nucleus and distinct blepharoplast. Delafield. 
Fig. 69. Encysted Crithidia with blepharoplast in contact with the very large nucleus. 
Delafield. 
